Two (very quick) minutes on their GitHub repo and it's pretty obvious that they're using firebase-analytics and at the very least seem to be sending URLs[1] and infos such as the model you download or the capacities[2] you use.
I was about to ask if anybody had looked at what it was sending home. I’m travelling so I’m not in a position to run this through a proxy for a couple of weeks, but also I’m travelling so this could be useful!
[0] https://github.com/google-ai-edge/gallery