I don't mean what he said I mean how he said it. The picture of the bear is petty and juvenile.
Then perhaps you shouldn't visit the Oatmeal. His site is full of that kind of thing. Some people like it, some people don't. You're apparently in the second group. ;)
It is intentionally petty and juvenile to draw the comparison that the letter from FunnyJunk's lawyer is petty and juvenile.