Make it exactly the same but add something you can think of. Trying to make this website not recognize it, so i can use it on a item.
This should be enough to fool your website's image detector, though I don't know which website you're trying to upload to, so I don't know if they use an uncommon one.
Not that anon, but the difference is that there's some noise added. The random local differences in color can throw off some forms of file comparison (like comparing cryptographic hashes) while looking mostly the same to us.
Pic related is an exaggerated example