Essentially it's a big cubimal which is made of multiple normal cubimals. Possibly requires some form of engineering (or toymaking?) to produce. Also provides a way to recycle excess cubimals.
But what does it do after you combine?
Personally, I wish it would tend my frickin' garden.
Or fly off to deliver your mail.
Or scratch this one spot on my back. Can't seem to reach it.
Maybe if you collect 11 or 17 of one cubimal you can cube them like making icons from emblems. Once they are cubed they turn into your pet and follow you around? Probably only be able to have one following at a time otherwise the lag from people having a train would be nuts!!!