From an interview with Juliana by Melissa Giannini for Nylon:

Giannini: You still have an eternal youthfulness about you. Do you think that’s helped or hurt you?

Juliana: Immaturity keeps me young! A lot of people who do what I do, musicians or artists in general, hold on to that youthful nature deep inside of them. Friends of mine in their 50s who make music, they still have that childlike aspect. They’re mature in other ways, but they never lose that sense of hopefulness or openness to ideas. Art is about playing and experimenting. Plenty of people play their old songs without any feeling and make a lot of money doing it, but I never really made a lot of money doing this, so it’s not worth it to me to just go out there and bang out the songs and not care.

The photo is by Tony Luong. There's a higher res version together with another shot not used in the article at