Summary:
There are some missing textures related to the Smithing Table in Texture and Mashup packs made by Minecraft.

Missing Textures:

• Plus icon in the Smithing Table UI (All Texture/Mashup packs)
• Smithing Table Sides (Cartoon and Norse Mythology only)

Steps to Reproduce:

1. Enable one of the official Minecraft Texture packs
2. Place down a Smithing Table and view the side textures and user interface

Observed Results:

The Smithing Table plus icon is unchanged in all official Minecraft Texture and Mashup packs. The Smithing Table side textures are unchanged in the in the Norse Mythology Mashup and Cartoon Texture packs. 

Expected Results:
The plus icon in the Smithing Table UI should have a unique texture like the plus icon in the anvil. The Smithing Table side textures should have unique textures in the Norse Mythology Mashup and Cartoon Texture packs.