I kind of assumed this was common knowledge already. Dove had an campaign pretty similar to the video, that was popular when I was in college it came up a lot in my classes. About 7 years ago they tried to use that same idea to sell products but by exposing it and pushing the opposite... marketing themselves to "real women" Also started featuring models of all sizes and shapes etc. They've kind of stuck with that theme since and it seems to be successful. They also have a good product.
I had a friend who studied graphic arts and used to do this professionally. It's a pretty specialized skill. Lot's of folks have photoshop, but that level of alteration I don't think is something you're going to find on the average cam model's photos unless she has a modeling contract, paying a lot of money, or has studied it extensively. Likely a little blemish fixing here and there, some touch ups, but not generally comparable mainstream ad campaigns.
Often when you pay a photographer for photos you're likely only getting one or two of the set photoshopped and sometimes not even done well. (I had some done years back the photoshopping looked crrrazy.)
I'd say expect to find this kind of thing in the magazines. Do people still read magazines?
But I mean in the camgirl sense... you can see them live if you want to know if they look that different... It'd be rare to find many, if any altered to this extent. When they are it's fairly obvious.
It's likely detrimental in mainstream media, and has gone on so long it's kind of the norm. It makes money on a subconscious level. Self esteem and all that fun stuff.