My suspicion is that it's merely representative of one of the game puzzles. If you did Cliff's April Fool Treasure Hunt this year, then you'd have seen these sort of squares used in that - but there was a grid to go with them in that. Mind you, having stumbled across this one, I then immediately started hunting across the site for others (as you tend to do, after doing the Treasure Hunt puzzle...
(note: I see that the shipping date has slipped *again* - and the wordsquare has now gone, to be replaced by what looks like it's going to be some sort of tangram puzzle.)