It is an odd one, especially given it's on Channel 4. Despite their new ownership they do still tend to stick to the BBC for covers.
Can only assume it sold rather well last year and they want to replicate that. Better than the year they put Wallace and Gromit on for no particular reason (than the usual repeats)!
That is a myth! They DID feature W&G in 2010 for a reason. They had teamed up with Royal Mail to launch a competition based around W&G because W&G were the subject of that years Christmas stamps. Plus ALL Wallace and Gromit films were being shown. After all, isn't The Snowman and the Snowdog a repeat too?
Well, just as tenuous a reason as this year then in that case. I don't remember the joint RT/Royal Mail competition particularly setting the world alight - probably more a case as with this year that the image would sell the magazine and they then needed a reason to justify it.