What I expected to happen was that when I held the barrier block in the hand, the texture for the barrier block would appear.

What actually happened was that even though I held it in the hand, the barrier block texture didn't appear.

Steps to reproduce:

1. Place down some barrier blocks.
2. Hold the barrier texture in you hand.

Note that this isn't a resource pack issue, nor is it a mod issue, as this has been tested in vanilla Minecraft under the original resource pack.