Mozart's ear

I find this comparison of Mozart's ear with that of an "ordinary ear" to be interesting for a couple of reasons. First, it's apparently the work of Mozart, himself. You can see "mein" crossed out and Mozart's name written in by somebody else. Second, I would love to know who got to represent all the other ears in humanity for the purposes of this comparison. That made me smile a little. Finally, is that an earring, Amadeus?

Via Harvard's Houghton Library Autograph File