Found a graphical glitch while playing in the 1.8 snapshots
How to Reproduce
1. Log in with an account, and open a LAN world
2. Re-open your launcher, log out of the first account (but keep that game open) and log in with a second account
3. Have the second account join the LAN world
The textures as you can can see are all over the place.
This issue has been reported already. It has been linked to the original bugreport.
Please search before reporting any bugs, as it's likely that one exists already.