Would need some better pictures of the Orpington, plus age. A picture of the full side view of the bird would be best, and maybe an overhead shot showing its back.
My first impression is that it is a cockerel, but it may just be due to the way the sun is hitting it in the photo.
I agree with OneHappyRooster. The Brahma is definitely a cockerel. The Polish, at 4 months, would be showing male specific feathering if it was a cockerel, but it isn't. It is a pullet.