This is great :) 10 years ago I'd been using Animata http://animata.kibu.hu + kinect, this rolls it all into one web based thing. cool stuff. Would it be easy to move it to a local GPU accelerated version for more FPS?
Hmm tfjs does use the gpu, and there are plenty of small models for posenet to run fast on mobile. Maybe this is an old version. (Or maybe the bottleneck is in the face or svg stuff)
But to answer your question, yeah it could be faster (everything could be faster given enough time! :)