If a gravity block (sand, gravel, or anvil) is placed directly above a corner piece of a chorus plant, it will break a few pieces of the plant, then break itself. On the other hand, if it falls onto the corner piece, it doesn't do this, and simply lands normally without breaking anything. It also doesn't break the chorus plant on any other pieces except corner pieces.

To reproduce:

1) Grow or find any chorus plant.
2) Place a block of sand, gravel, or anvil directly above a corner piece.
3) Watch what happens.

Considering the inconsistency between what pieces it affects and how it acts whether it's falling or placed directly, it seems too strange to be intended behavior?