It Looks Like ...

Mabel's left turn signal is stuck!  She must have flapped her ear into something, or scratched it too hard, because all of a sudden the outer edge puffed up like a balloon, and now her ear is sticking out from the side of her head in a very odd fashion!  It doesn't seem to be bothering her, but it's most definitely swollen.  If it doesn't subside by itself within a couple of hours, I'll have to give the vet a call.

UPDATE:  I just got back from the vet's office.  Just as Dr. Subjunctive posited, Mabel has an aural hematoma, caused by scratching/flapping her head around due to an ear infection.  She received a treatment for the infection today, and has to go back to the vet again on Saturday for another one.  Once the infection is better, we will then have to decide how we want to deal with the hematoma.  We have three options:  (a) Do nothing, and let it go away by itself, possibly leaving her ear looking misshapen, like a boxer's cauliflower ear, (b) Aspirate with a needle, which the vet told me was very painful and unpleasant for the dog, or (c) surgery.  Ugh.  None of those choices sound very appealing!