The closest I’ve come in real life came some time before my “official” testing career, where I spent some months testing the software for car windows and sun roofs. Before then I never even knew those things HAD software.
The reason I mention this is that my test approach might be similar. We’re dealing with a motor, some moving parts, and potential access to things which aren’t supposed to go in there!
It’s that last point which I would likely approach first. If everything else on Floor-a is perfect, but some kid loses a finger, then your business is done. If Floor-a (by the way, great name, I’m using it for all Roombas forever now) is loud and only picks up half of what it’s supposed to do, you will lose customers, but you may recover.
So the first thing I will do to the thing is pick it up. When I pick it up, does the motor stop? And not just go into coast mode and spin to a halt… It has to STOP. (Don’t have one of my own, but my in-law’s robot grass mower does just that).
My next bit of test tooling would probably involve a ruler. Are there any gaps big enough to fit a baby’s finger in? How about a cat’s paw? (and no, as a software tester, this isn’t technically my job, and yes, I would STILL DO IT)
Even if there isn’t enough room for curious appendages to find more trouble than they want, I would still put big things in the brushes. For the windows thing, we used sticks of balsa wood. That might be appropriate here too. We don’t want to require a lot of force to trigger even more safety features. (This being said, elastic is a fun testing tool, as it could gum up the works. My daughter’s hair is a brilliant tool for killing hoovers.)
I could go on, but I won’t. But after a seemingly absurd time thinking about ways someone could hurt themselves or their house, I could then start thinking about “does it do what it’s supposed to do?”