No? Well, I have an answer for you anyway, though I'll admit it's part guess: it's because LJ doesn't hold the copyrights to The Simpsons and Scooby-Doo, so it didn't use images #3 and #4 from the bottom row.
Update: The above-described images have since been deleted from LiveJournal's servers.
In the same directory is this nifty icon, of provenance unknown to me.
The only other weirdness here (that I'm aware of, at least) is one you've probably all noticed already: the "thumbs-up" icon is also used on the User Profile (userinfo.bml) pages of Paid and Permanent Account holders.