hiding items as an associate

I was working with someone today and I asked if they had a certain item over in their section, because I intended to buy it after work, and they kinda huffed and were silent for a moment, and then they said "Yeah I hid one on the top shelf so I could buy it after work" which doesn't make any sense to me because we literally can hold items????

I said "Oh if you are buying it Ill wait til another comes in" and she sighed again and said "No its fine just buy it, Ill use the one at my job". I watched them throughout the rest of the time and they kept hiding stuff in a similar spot 😭.

The item was a heavy fitness vibration plate. I feel like it is dangerous for customers to grab an item of that weight from a top shelf non the less, but also... is it not against policy to literally HIDE items for your own convenience....? It feels morally wrong. Could she get in trouble for that?