When holding a Pocket Computer or a Printed Page it is rendered twice, once large, held in both hands (like the vanilla map) and once smaller, held just in the main hand (which is added to the two "regular" hands, rendering three hands).

Steps to reproduce:

1. Get a Pocket Computer or Printed Page.
2. Put it in your currently selected quickbar slot.
3. Observe.

Minecraft Version: 1.14.3
Forge Version: 27.0.13
CCTweaked Version: 1.83.1

When a shield (or any item) is held in the offhand slot and a Pocket Computer or Printed Page is selected in the main slot, it is rendered twice, too. Both views are the small version, once in the main hand, once in the offhand.

Looks like this is a Forge bug - I clearly failed to fix things correctly the last time. Woops!

Should be fixed by MinecraftForge/MinecraftForge#5927.