No, he means cut the entire plastic off from the top of where the comic is when standing up the card. This is where I cut it as well, because as Sharky says, if you are cutting just the extruding bubble (which is the middle of the comic), and if the knife catches on the plastic and suddenly frees itself, you are likely to cut into the comic.
I cut along the top of the plastic portion, slide out the comic and then cut the rest off. I'd never cut mine the way they are described in those photos... it's just too risky for the comic, and the toy, and more hassle trying to cut into a rounded surface of the bubble.