Interlocking tiles that do not interlock

I appreciate the effort of trying to make the interface more intuitive, but I am having a bit of trouble with the shapes of the tiles for arguments.

We have interlocking pieces, but they do not interlock with anything. The little prongs are too small and the shapes used have no relation to the data types they represent.

I know that idea is closer to drop-in puzzle pieces than to interlocking puzzle pieces, but, like drop-in puzzles, there is no need to use those kinds of shapes with those tiny prongs.

Like in the previous version of Alice, I would go with a combination of colors and shapes for each of the data types. Simple flowchart-like shapes [ ], < ___>, /__/, etc, are easy to distinguish without requiring new prescription glasses.