Err, i feel you're making up some sort of headcannon that isn't quite there in the game? Axel is pertty explicit about the Wildcat thing in his texts:Ivy and Lena aren't established models. They're amateur insta-models (Peoplegram models), they don't work for any agency and very few people know about them. Cindy was selected because her modeling is more sensual and artistic, plus her beauty is all natural (Ivy has fake tits, piercings and lots of tattoos and basically sells porn on her Stalkfap). Wildcats simply view Ivy as trashy based on her portfolio and I imagine Lena's entry was too late so they already made up her mind about Cindy when Axel presented them Lena's portfolio (IF he really did that and didn't simply lie to Lena to make her pose for him some more).
Python:
x "{i}Anyway, I just wanted to update you on the modeling agency situation.{/i}"
x "{i}I presented them your portfolio and they liked it, but they were only interested in hiring a new model for the summer campaign and they gave that spot to another candidate.{/i}"
(...)
l "{i}Just one more thing... Out of curiosity, who was the girl that was picked by the agency? Was it Ivy?{/i}"
x "{i}No, it's the other girl I've been working with. Cindy.{/i}"
l "{i}I see... Ivy won't be happy about it.{/i}"
x "{i}I tried to get her in, but her style isn't quite what Wildcats is after. They're looking for something more... sophisticated.{/i}"
The "sophisticated"/"sensual, artistic" thing is probably right, although i suspect it boils down more to Cindy not (yet) being used/comfortable with being openly sexual with her posing. Though it, again, strengthens the idea that Ivy and Lena have some modeling presence that's known to more than few people, and in this case that worked against Ivy -- if they were unknowns then having more bold shots in the portfolio would matter little; modeling is largely about presenting required persona after all.