If we had the original, we might have more information about this particular photograph. The studio at which it was made might be printed on the back, and from that we could guess better when it was taken. But since Benjamin doesn't look wounded or sick, the photograph probably comes from soon after he enlisted.
Benjamin's uniform appears to be made of dark blue cloth rather than the butternut, or gray, that we always associate with the Confederate troops. Apparently Confederate uniforms were not, well, uniform, until later in the war. This photograph could show Benjamin in the uniform of the Georgia militia, which was dark blue. He is wearing no insignia on his sleeve, but he may have insignia at his collar. It's hard to tell. His belt buckle seems to be a standard-issue CSA buckle. His hat is called a slouch hat. What the star is doing on that hat I don't know. He is wearing a fancy sword, and a sash or scarf. Too bad color photography hadn't been invented.
But, in spite of the limitations of this photograph, it's fascinating just to see what Benjamin Hardin Newton looked like as a young man. As far as I know, this is the only photograph that exists of him.