The hollowness of villagers' heads is revealed when they shake them

When a villager shakes its head, the bottom texture can be seen from behind, revealing that its head is hollow. This is slightly unsettling and is to my knowledge inconsistent with all other mobs whose bottom head textures can become visible.

To reproduce

1. /summon minecraft:villager ~ ~ ~ {NoAI:1b}

2. Right-click the villager from behind, and look at its neck area

Expected behavior

The bottom texture of the villager’s head would not have a black square suggesting hollowness, and/or villagers would have a neck that prevents this area from being seen.