I don't see how the right looks any younger than the left. It's just a different facial structure. While I prefer the left and think face edits like this are dumb, it's inconsistent and frankly comes across as obnoxious to dismiss these complaints with the opinion that she looks better on the left; to those making the complaints, she looks better on the right.
There are differing beauty standards in different countries. There are also different facial structures in different country. Whether or not beauty standards should play a lesser role in general, is not the same as heralding your own cultures beauty standard above another's. And if you are going to counter by citing Japan's culture's sexism and/or pedophilic tendencies, at least make an effort to point out the connection between that and the scrunched up face we see here. The insinuation that making a characters face less long = making them look children is offensive to me. In my experience as an Korean American, the less experience someone has with people of my ethnicity, the more they are likely to mistake me for another that looks nothing like me, and also the more likely they are to vastly misjudge my age. However, it doesn't come as a surprise to me; given how complex a computational problem facial recognition is and how large a portion of our brain is devoted to it. It should be obvious that it's affected by various subconscious and nuanced pattern association and learning mechanisms, which extends to circumstance and culture. You could do some cursory research to find that East Asians generally have a fixation on the relative size of one's head in the way the West does not. And, notably, in a manner that is generally universal across gender and age. Is this particular edit a rounder head associated with neotenic traits or a smaller head-body ratio which would be a more adult like characteristic? Was it ever acceptable to call the fan edits of Hope's face (Mirror's Edge) in which they significantly enlarged the eyes, looking like an alien, when there are actual people who look much closer to that than the original (plastic surgery or not)? If the issue is truly about oppressive beauty standards, then how is the response, she looks prettier/more beautiful without the edit not self-defeating?
If anything the edit makes her appear more kawai just like in the Cammy case, but the link between the kawai cultural phenomenon and pedophilic degeneracy is clearly more nuanced than the rhetoric here makes it out to be.