This is not a natural curve, look at how the hoodie and hair warps around it.
It's subtle things that we may never pick up as we become desensitized to the standards of Instagram content, however after following r/instagramvsreality on Reddit which constantly points things like this out, you can't stop noticing it. Most influencers are photoshopping now.
Exhibit B: look at how 2D she's made her body look by airbrushing it as one colour and removing the natural shadows. Plus the blurs on the areas she's warped.
Her younger audience don't notice this and it's kinda sick that they're probably worshipping and wishing for her body when Ana doesn't even have that body.