No, I agree she doesn't look like Olivia Dunne. I'm simply making a point that looks are a huge part of endorsements, especially for young women. She's above-average looks for a woman in her mid-20s and that's huge when you're also the best basketball player in the world (I assume she's up there if she isn't).
I think her endorsements are probably MUCH more than they'd otherwise be, based upon her looks. On the opposite end of the spectrum, what would her endorsements be if she were ugly? Hard to say exactly, but I'm thinking less than $1M instead of about $11M.
Comparing her looks to Olivia Dunne is also not apples and oranges. Clark is playing a much more popular sport with women that have different body types from gymnasts. I guess a simple way to put it is that the bar is different for good looks to be able to help you bring in money.