He doesn't appear to be, to me. The best way to tell via photos is to place them in natural light and take a picture of the face, the nose will pretty much always have a distinctive sheen of light around it with a darker area right at the end of the nose.
Not the best picture to use to explain but you can kind of see it on my satin Finley here.
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If you're at all concerned your vet can confirm either way for you as all satins have hollow hair shafts when looked at under a microscope, this is what gives them the extra shine as opposed to just a regular shiny coat on a healthy animal.