I am a little confused. I purchased shelf brackets in the exact size of the previous ones I had for this shelf. The new brackets however extend a bit further past the shelf itself ( not the depth going down ) but the width. Is this an issue? I plan to put hanging plants and could hide the extending piece of the bracket but is there a safety concern with this. I plan on putting very light items. I am just as to confused as to how they say they are the same size but aren't really.
If they were the "exact size of the previous ones" you may have them rotated "the other way" - many shelf brackets are not the same length on both legs, so you may have had the longer leg on the wall and the shorter leg on the shelf in the previous installation, and the longer leg on the shelf this time.
Flip them around and see.