If you put down an item frame created with: "/give @p item_frame{EntityTag:{Invisible:1b}}" items placed in it are closer to the wall than if you put an item in an regular frame. So if you Put a torch, a button, a pressure plate etc. into the item frame, the item doesn't show up in front of the block (torch, button,....). If you do this with an visible frame it works normally. It would be quiet handy for builders if it would work again. 

Attached some examples: