Put the summary of the bug you're having here
What I expected to happen was...: Have the shovel texture.
Describe what you thought should happen here
What actually happened was...: the pick axe texture came up.
Describe what happened
1. ... *have tools in your hotbar and switch in between them.
2. ...
3. ...
I find that this happens specifically with diamond tools as your picture shows and that it's very common (it's easy to reproduce) I've never seen the bug with any other tool type. I am on ipad3 and android 4.1 phone.