When I'm sneaking while holding a shield in my main hand, it looks like I'm actually using said shield to block attacks.
Steps to Reproduce:
Hold a shield in your main hand.
Sneak.
Expected results:
The shield should look like if you are not sneaking.
Observed results:
It looks like we are trying to block with the shield.
This is working as intended. From the 1.10.0 changelog: