Making a desktop pet feel present: animation, window motion, and the quiet moments

A dog can look convincing in a video and still look wrong when it walks across a desktop. We ran into that while building Mocha Casa, a Windows pet companion made with Electron and JavaScript. This is a development note from our own project. The useful part is the small set of problems behind the demo: synchronizing movement, handling transitions, and giving the user control over a companion that shares their workspace. The intent is to let someone see a familiar pet beside their work, especially when the real dog or cat cannot sit there.