So I was looking at a model's set, and I noticed that some of them have the tags like "perfect tits" or "perfect ass" etc... and from what I could find most of them weren't tagged by the model herself, but rather others. Which I think is interesting, because there's no such thing as the "perfect (body part)", and I think some of those same tagged models would agree.
First off, just like beauty is in the eye of the beholder, no 2 people find the exact same thing perfect. Take breasts for example. One may prefer obviously fake gargantuan breasts; another may think that flat chested is the best. One may prefer them globe shaped, while another likes them pointy. One may want large nipples and areola, while another prefers them small and shaped like pencil erasers.
And that doesn't even count that some women (just like all humans) may not think their features are "perfect". One could be told her apple shaped ass is perfection, but she's always envied other women with petite little hind ends; one could be told her large breasts are perfect, but she's tired of the back pain and would much rather have smaller ones that could fit into any clothing off the rack. You get the idea.
In the end, YOU may think a physical feature a person has is amazing, spectacular, and very impressive; but even if that feature is perfect for you, it doesn't make it "perfect" for anyone else, least of all that person the feature is on. Ultimately, there's no such thing as perfection, just preferences.