Sending pictures to supplier during sourcing phase in China

I learnt something when doing sourcing a few years ago : never send a high resolution picture of your product to a Chinese supplier.

One day I was sourcing a product i had design myself on a b2b platform. I had taken very nice picture of my product after doing the prototype. I even ask a photograph to improve the picture to make it very appealing.

I started to search a supplier on a b2b platform and naively was sending description of my product and gig resolution picture by email for them to quote.
Believe me or not but no less than 12 hours later I had already 2-3 Chinese manufacturers who took my pictures and put them online on their b2b account to promote the product which was not even entered into manufacturing yet.

I had to contact all them back and to threaten them to push them to remove my picture.

Lesson learnt, I would never give anymore any picture in high resolution and not being watermarked to any supplier.