At some point the good angle stops being luck. She knows which side of the restaurant mirror catches her face. She turns before the photo, just a little, so the camera gets the line of her neck and not the awkward overhead glare.
It can be small. Sitting sideways on a chair with one elbow on the table. Looking up a second late. Letting the group photo happen without hiding behind another woman’s shoulder.
The picture still looks casual. That is why it works. But there is control under it, the kind nobody can point to without sounding too interested. So they just keep looking.