First, let me say, I really like the tanned skin character. .
Perhaps they are referring to the paint on the woman in the top left screenshot? Her white lips are not as natural looking as the rest of the characters’s lips. Perhaps this is what they talk about it not looking being blended. Which makes sense… Its white paint!
I don’t know about PS or PSP, but in gimp, if you select the area around the lips using the fuzzy select on an alpha channel where only the lips exist, hit grow selection by 5 or ten pixels, then blur it, you should get rid of that… that’s assuming you have the lips on their own separate layer.