Items,Blocks, Entities, Particles in Nether are visible in overworld

_emphasized text_While playing with my son he noticed that he could see me mining in the nether while he was in the overworld.

He hosted the game, iPad 2 (I think) MCPE 1.1.5
I was playing on Win10 MCPE 1.1.5
The screen shot was taken on iPad
This is a local lan game