Some say she's excited, some say nervous about something.
I say keep an eye out for this behavior, if she does it again, note her surroundings, what she's looking at, etc... Check her drawer for any signs of anything odd, in the meantime.
It might possibly be related to the lipoma and ointment , making her tail feel a little odd... It's really hard to say. I'd just keep an eye out, but I've read about other tiels doing it, for different reasons.
Here's a link to a thread where someone is asking about it, but she says her bird does it all the time, usually when content or happy. She made a video. It's in the thread It's hard to see, but you can barely make it out if you look at the bottom right tailfeather.