can't tell if i have a glue spot or nail mark on the edge my iPad

i just noticed this glue or nail mark on the left side i'm hoping it's only glue but my question is what is a good solution to take glue off if it ain't i just might take it back to apple n have em check it out, hear are some pics i took with my 4s there right in the middle... it's not the best pics of it but you can see somethings there.

 

Don't see a thing friend. If it is in the black border or on the edge, you will never notice while you are giving your attenion to the screen. Not a even a little deal in my opinion.