Strange place in the cave below the staircase

[Slith265 5]

Ok, first this room was filled with crystals but once you use earthquake it grants acces to the stairs behind my character, i try to interact with that square in the wall but nothing happens and at this point i don´t know what to do. I dont remember that door over there to access to the room but i think maybe it was added in the E16?

If someone knows or discovers a thing to do here in this place, please put it in the comments.

[Amine 171]

There is supposed to be a Green pokeball ( a field effect reading) in that room

[Slith265 5]

thanks, i thought that it would be more epic. man i feel a little upset now hahaha