Can u put a paper between the screen and the middle frame

[91xxiong]

At first, I thought only my phone could do it and that's a defect. The difference of the gaps on each side is relatively noticeable. So I called Tmobile to get a replacement.
But then I tried it on my gf's phone. It could do the same thing although there is no difference between left and right.

Does anyone have the same issue? I am afraid ours are not water resistive any more,