I just picked up this 1858
Flying Eagle cent graded by Anacs as VG 10, no issues. However on the reverse right above the "N" in "Cent" there appears to be something unusual. Is that just damage that Anacs missed, or something more interesting? I've included an image of the obverse to show their grade of the coin, and then below is the mark indicated by a green arrow. Interesting the mark appears to be a mirror image of the very top of the "N" below. Thanks in advance for any input.

