Today I was looking through my cards and happened upon this strange square in the center of my card which I thought was odd. What could it be? Is it an error? Is it worth less?
Am I seeing that the light is shining through the card, highlighting that square? OR is it a reflection of some kind?
I think it is the case. I have the odd case with a square like this and it really annoys me.
Dead pixel 
Debris from the sonic welding process of sealing the slab. Its not on the card.
Very common square in the PSA plastic case, no value added or removed. Carry on
