This piece has been sitting on my office desk, in a vinyl flip, for about two years now and I just noticed this....... Feel free to post yours too.
Here's what to do: let 'er tone, send 'er to a grading company, and reap some rewards, LOL! Jokes aside, that is a very nicely toned ASE.
It’s not a dark toning so it shouldn’t hurt the silver round. It’s a beautiful champagne toning so I say Let It Tone!
I have an ASE in a flip that's doing the same thing, on the obverse and a little on the edge, nothing on the reverse (yet). It's been sitting in my open desk for about 4 years now.