When lining up items with an anvil, they will line up on the side of the block and be affected by ice, typically making an item go faster. (Similar to ender chest trick, where items can go into a hopper on the side of the block.)

However, when the items are lined up with the east side of an anvil (when the anvil's metadata is 0), the ice does not affect the item.

Steps to Reproduce:
1. Build either/all "bug1, bug2, or bug3" screenshots below, keeping in mind the direction.
2. Put item in water stream before anvil, notice they keep the speed after the turn
3. Build "bugactual", keeping in mind the direction.
4. Notice how after the turn, the item does not have the same speed.