I noticed this happening myself but hadn’t seen the entire evolution of the ad.
Some viewers may find the following scenes upsetting:
Online ads for the game Evony started out like this:
Then they added a woman with a little boob showing:
In case people weren’t noticing the cleavage, the ad evolved into one where the boobs are pointed out a bit more explicitly:
Moving on to a slightly more realistic look:
And then they realized they could just dispense with all subtlety and get to the important part:
Players will be disappointed to find out there isn’t even a female queen to be saved in the game.
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And here’s the last ad, live on the web with those CGI boobs in context.