First listing, completely random pics in my product, wth?

I listed my first product as an individual seller. I had to apply for GTIN exemption and post it as “Generic” brand. So far so good, except after getting published, I have pictures of t shirts while I’m selling something else. No idea where these come from. Looks like some stock pictures.

When I try to edit the image I have this message on top:

“When multiple sellers sell the same product through a single detail page, we combine and present the best product data to ensure customers get the best experience”

Except that the description etc is mine.

Could anyone help me understand what is happening and how I can get my images up?

Thank you