I think the first two are much closer to minimalism too. IMO, generally, for a minimalist image you have to use a limited set of colours that either contrast strongly with each other, or are a narrow range of tones. I think the first two photographs work better for that reason. I am sure there are literally millions of minimalistic photographs online, but you might like Amad Bahi's photographs. He is a member on RPF but he hasn't posted for quite some time.