Shields sometimes momentarily change position in third person when blocking attacks

The Bug:

Shields sometimes momentarily change position in third person when blocking attacks.

Steps to Reproduce:

1. Summon a skeleton, give yourself a shield, and switch into third person.
2. Switch into survival mode so that the skeleton attacks you and watch closely as the shield blocks the incoming arrows.
3. Take note as to whether or not shields sometimes momentarily change position in third person when blocking attacks.

Observed Behavior:

Shields sometimes momentarily change position in third person when blocking attacks.

Expected Behavior:

Shields would not sometimes momentarily change position in third person when blocking attacks.