It is partly that but also that most of these people know the poses that enhance it way more than just standing normally. That along with angles and purposeful crops can make most, even flat asses look good.
Then ofc there's digital editing. Which we all know varies from album to album. I think her most common trick is more or less a butt pose with some digital editing to round it out. Any time legs are crossed in some way it's basically a pose to make the ass look bigger while making waist look smaller and also creating the 'illusion' that it actually sticks out that much without having to bend over. Same thing with putting one knee/foot in front of the other.
It's one of the reasons I personally don't like most cross-legged pics cause I feel like that pose, compared to simply bending over, is a bit more of a lie. Cause they usually also need to crop to create this illusion.
If she had a butt-lift it's not too bad considering it tends to follow how thick her legs are at any given moment. When she got heavier for a while it did follow accordingly, when she was thinner it was proportionate but well shaped too.
I didn't intend to make this into a whole post on whether her ass is fake or not but I was curious if she has any picture at all where her angle/pose is actually not an ass enhancing one and this is one of the few I saw that also lacks most of the editing we see in for example Patreon sets. Again, this is NOT to try and prove her ass is 100% augmentation free. It's more about poses that gets used repeatedly and how much it matters. But in the above pic her ass looks smaller than normal, despite having one foot placed in front of the other, simply because the angle isn't good for it.
It's actually kinda annoying going through pictures like this knowing about the leg placement trick because of how fucking often it's there. And when I initially started seeing this leg placement thing I started appreciating all of those photos way less.
Some pics where she seems to have legs somewhat parallel(again cropping could fool the eye). The ass doesn't look quite as bubbly because of this. But they're extremely rare. Especially these days. They were more common when she was thinner but yeah she was also less trained as a "model" back then. She's still bent over slightly in this pic so foreshortening makes her waist look smaller.
Sorry for the wall of text.
This wasn't to say she's never had a butt lift. And considering she's had many cosmetic surgeries it wouldn't be out of the question. I'm just pointing out that she's at the very least
also using angles/poses/editing that makes it look better overall. In the pic the other dude linked for example one leg is put forward, and it's heavily edited like patreon sets.