They keep using the term "motion sensor," probably to avoid saying "this device that you will place next to your kid's bed has a camera and an internet connection."
(related community if that makes you nearly have an aneurysm: !privacy@lemmy.ml)
edit: OK, it probably doesn't actually have a camera, see comment below. I assumed it had to, since it mentioned detecting "hand gestures." However, that could mean that it just roughly detects you waving in front of it, which wouldn't require a camera. I still hate it.
The features described could be accomplished with a PIR motion sensor. I don't see any reason they'd go to the expense of adding a camera, especially since infrared is better for operating in the dark like you'd expect for an alarm clock that'll need to be able to wake kids at 6am in the winter.