Block textures changing when hit for one persons perspective in multiplayer

I was exploring the beta in creative with my sister, both on moto g fast, and only from her phone when she would hit a block, the texture would change. Grass blocks would turn to granite stairs, stone to pistons, and others. But it is weird that it was constant, all grass blocks would turn to granite stair and all stone to piston, other blocks did different texture changes. Also at one point she found a what looked like maybe a chest hit box with a green line going to it, also only visible on her phone. This is super weird, but I hope you will be able to figure it out 🙂