I noticed something similar on projector carts, those mobile stands used for movie projectors.
On the side of each of those is a pictogram-based safety label. It depicts a person pushing the cart, but an X through a person pulling it, for example. But the first item was always a taller figure standing next to a smaller figure, with an X through the latter, indicated it should be used by adults only. Not too long ago this was modified to both a male and female "adult" figure, and an X through a shorter "boy" and "girl" pictogram.
I tried to find a picture of this label/decal online, but the best I could find was a catalog item for that type of cart -- and even there, you need to mouse over to zoom in.
https://www.displays2go.com/P-21117/AV-Carts-With-4-Wheels?st=Category&sid=28608