Here's HTC's response to an obvious watch showing up (look for it about 35 and 44 seconds in) in that design video from July 9:
"HTC encourages our design team to explore and tinker with new ideas and even models, as is the case with the watch some viewers noticed in our recent HTC Design video. It in no way indicates an actual product HTC is planning to release. Keep an eye on this space for exciting new products from HTC when they are ready to be announced!"
So, yeah. It's a watch. Or a design of a watch. Either way, not a real product. The good news is we can still expect some Android Wear fare from HTC, as it's still an official partner. We just don't know when, or what, we'll eventually get.