When an entity is on top or on the edge of a powdered snow block, there will not be a shadow as if they were standing on any other block.

What I expected to happen was...:
I expected to see the shadow of the mob on the powdered snow block.

What actually happened was...:
The mob stood there without a shadow.

Steps to Reproduce:
1. Place a powdered snow block.
2. Place a mob on the powdered snow block.
3. Observe the lack of a shadow on the powdered snow block