Hmmm..., It could be the condensation as pat007 has posted, but I noticed that she is also rubbing the seal to claim it as hers, and the condensation would have been licked off quickly, but she continued to lick. She may have been attracted initially from some odor coming off of the seal, and has now found the taste and/or texture to her liking.
You could try cleaning it with something non-toxic, such as a diluted vinegar solution, and see if this stops her. But I am a bit baffled, and will have to do some research.
Thanks for posting the video.
I would suggest she is licking the condensation off.
Do you have fresh water availble for her?