Summary:
Entity shadows are not showing when the player stands inside some incomplete blocks without collision. If the entity is above these blocks, the shadow will be showing on these blocks.

List of blocks (maybe not complete):

• Snow layer
• Item frame
• Pressure Plates

Steps to reproduce:

1. Place the above blocks on the full blocks (for example dirt).
2. Stand on the placed blocks.
3. Look at your shadow from a third person view.
4. Jump while looking at the shadow.

Observed results:
Shadow is not showing on incomplete blocks when an entity is in them.

Expected results:
A shadow is showing on incomplete blocks when an entity is in them.

Original description:
Mobs don't have shadows on snow