Rose and George Byrne are quite rare: celebrity creative siblings who are as open and friendly as they are talented. Where some actresses can be reserved or aloof, Rose immediately volunteers that she and George are heading to a friend’s wedding in Greece on the weekend with Davidson – “We’re all going together: Will’s best friend is getting married and he and George are the best men” – while George confides that their shared sense of humour grew out of their joint Seinfeld addiction.

“Seinfeld is like comfort food for us,” he says. “We were obsessed with it growing up and people actually call me Jerry now as a nickname, so maybe it’s all caught up with me.”

He and Rose may have spent their formative years watching endless episodes of the American sitcom and Britain’s Fawlty Towers at home in the leafy Sydney suburb of Balmain – “Basil Fawlty is my comedic hero” says Rose – but it’s now the willowy brunette who commands the laughs. Her big comedy break in Get Him to the Greek with Russell Brand led to Bridesmaids with Kristen Wiig and Bad Neighbours and its sequel with Seth Rogen. Yet she’s equally compelling playing it straight: she earned two Emmy and Golden Globe nominations apiece for her role as Ellen Parsons opposite Glenn Close in the legal thriller Damages, and also impressed in The Place Beyond the Pines with Ryan Gosling and Adult Beginners alongside her partner Bobby Cannavale.

She and Bobby now live in a brownstone in Brooklyn with their 17-month-old son Rocco, while George is carving out an impressive art career from his home in Los Angeles. His striking photographs, that reveal the beauty in the banal buildings and landscape of the City of Angels – “breaking it down, one palm tree at a time” he jokes on Instagram – have garnered the artist and musician more than 92,000 followers and significant interest from the wider art world. He is represented by the Olsen Gallery in Sydney, which featured his solo exhibitions, Local Division in 2016, and Colour Field in June this year. In between was a residency at Soho House in LA.

George’s upcoming show, New Order, will feature more of his signature aesthetic, combining geometry and colour theory to evoke a sense of urban isolation. Opening at New York’s Olsen Gruin gallery on 15 September, it is part of the artist’s ongoing quest to forge a new path in photography:

“I’m pushing the medium away from straight documentary or portrait because I’m more interested in creating a feeling than telling a story.”

He cites artists including Jeffrey Smart, Richard Diebenkorn and Stephen Shore, a member of the New Topographic movement of American landscape photographers, as among his influences when it comes to capturing unexpected California moments.

“I love the idea of accidental beauty, and I’m most satisfied when I can make a good image out of the most unlikely scenery or surfaces,” he says.

One of the first people he shows his photographs to is Rose: “She has a really good, natural feel for aesthetic, and she’s been really helpful as a sounding board over the years”. That respect for each other’s opinions reflects the deep bond between the pair, who support each other in their professional and personal lives.

“We have a great dialogue and, while we are in different businesses, you obviously navigate a lot of similar things in the acting and photography industries,” says Rose.

“I learn a lot from George’s perfectionist attitude when it comes to his work, because as a Leo I can be lazy, and I always value his opinion on a film project or a screenplay, because creatively he’s got great taste. He’s got a great sense of humour, so he’s excellent to have a vent with if you’ve had a bad day, and we also just have that true closeness with a sibling that you can’t get with anyone else.”

The pair grew up in the late 1970s and ’80s with two artistic sisters: Lucy, who works for the Australia Council, and Alice, a painter. As the children of a primary school administrator mother and a statistician father, Rose and George are equally baffled as to how all four wound up in creative careers.

“I put it down to free-rein parenting where your parents are very comfortable allowing you to pursue the things you love doing,” says George.

“There was never any pressure to pursue a particular career and there was always a lot of unqualified support for the things that you were interested in.”

For Rose, that was immediately acting – “I was quite shy and as a kid it was a place you could express yourself” – but it took George a little longer to settle on a vocation.

“Rose has a laser-like focus for what she is gifted at, which is why she started acting from the age of seven, but I’m 40 now and it’s only been the last few years that I’ve been successful in what I’ve been doing,” says George.

“I had so many interests growing up that it was hard to juggle them to be successful – the old 10,000 hours theory – so in a sense I’ve been slower to achieve and get to where I wanted to be. But, while there is an argument for laser-like focus, I think there is also an argument for being open minded, so it’s always about finding that balance.”

Once George settled on music and art as his twin passions, his sister was ready to assist in any way she could.

“For my career she’s always been incredibly helpful in terms of using the resources she’s had through who she knows or what she’s doing,” he says. “She’s also a fantastic listener, which is why she has such deep friendships and why she is so great for advice.”

It was Rose who George turned to when he first arrived in New York from Australia.

“When George came to the States he lived with me for a while in New York before he went out to Los Angeles,” says Rose. “Coming from a super-close family, we are all deeply entwined and unwaveringly supportive of each other. It’s an unspoken bond.”

And when they do disagree, it’s simply a matter of giving each other a little space.

“We are both strong-willed and can be strong-headed sometimes in what we think,” says George. “Usually if we have a disagreement we’ll just have a cooling-off period to give each other a bit of a breather, but we’re fortunate enough with our personalities that we don’t tend to butt heads or scream and shout. We are both pretty intuitive and we tend to have similar views on things.”