I bought two pieces and their batteries were completely empty when I tried them, with whatever consequence this has on their battery life.
The Yeelight Drawer Light is designed to provide soft lighting for drawers and cabinets or something similar. Its sensor does not detect human movement because it was not designed for that, there are so many other lights for this purpose. The sensor consists of two infrared (or ultraviolet) LED radiation, one is a transmitter and the other is a receiver. If there is an object nearby, the beam of the transmitter reflects on it, so the light turns off after a short timeout (3sec), otherwise it stays on for 30sec. I haven't tested it, but it is likely that sunlight can put it in an Off state, meaning it won't turn on unnecessarily during the day.
It is a bit peculiar regarding its placement, as even a slight protrusion next to the sensor can reflect the signal it sends and not work as intended. Do some tests and don't rush to stick it somewhere if you're not sure it's functioning correctly. I placed it in the car's glove compartment, which had no lighting, and on the coffee maker to monitor the water level. I am on the first charge and very satisfied with the dimensions and the light it provides.

Basic detail. It does not have a motion sensor like many similar LED lights and wrongly I think it says in the description.

It has a small light sensor on the top which activates it when exposed to light. It needs to be placed in a position so that the sensor is covered and when uncovered, it is activated. So it has nothing to do with motion unless we cover the sensor with our hand. As soon as we remove our hand, it will turn on.

The package includes a metal sticker and the light has a magnet on the back. So it can be used, for example, to light up the back of a drawer.

I have placed it outside a drawer, under the scooter seat, and also at the bottom of the car door. It turns on when I lift the seat and similarly when I open the door. Of course, it took several attempts to find the right position.

The magnet for simple opening and closing of the drawer is satisfactory, but for other placements, it is not strong enough, so I have used blu tack and double-sided tape.

It lights up for 30 seconds unless the drawer closes earlier or something else activates it, then it turns off after 3 seconds. When there is a lot of lighting in the space, it does not turn on, and there is no reason for it to. It charges with a USB type C. Its autonomy is good and depends, of course, on the usage. In places where I have permanently placed it with double-sided tape, I use a power supply or power bank for charging when needed.