The answer is "no": however, given that, in reality, we have no evidence that it's stronger than the vanilla chess.com bot at level 25, it probably uses similar technology, which is likely to be the move selection code of an old (pre NNUE) version of Dragon loaded in to the browser as a WASM program.
However, it looks as though when a web service request is made from WASM, it doesn't show up in the browser's network tab (WASM probably doesn't ask the browser to make the request - it probably does it all by itself), so we cannot know for sure.
One test we could do:
* start a game against Mittens
* after the game has started, disconnect the network
* see whether this prevents Mittens from making a response