If an enderman is holding a block when it is killed, it continues to hold the block even after the block is collectible by the player, implying that the block is two places at once.

While this issue in no way affects gameplay, the visual discrepancy of a block being "in two places at once" temporarily can be at least a little unsettling.

See screenshot for example: the enderman is holding a sand block while the sand block he just dropped can be seen directly behind him.

This appears to occur every time an enderman is killed while holding a block.