Just opened the first bag of $25.00 of the newest quarters. Found 24 with a large die chip on the biplane's lower wing between the struts. Some of the chips are smaller and some are larger.
If this is what you are talking about it appears to be part of the design. Photo from the US Mint site.
I think they are referencing the blob on the top of the wing, looks like a possible die chip. (OP's photo)
@LakeEffect Thank you for pointing out what should have been obvious for me to see. I somehow read below the lower wing.