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the galeries are image-only. So you will not see them in SERPs for any querry without brandname I am sure. No Penalty for same alt and title, its better to use allways the same alt for the same image. What these Galerys are: Thin content and maybe duplicate content - because no content but images. Additional information for the images (maybe on hover, next to the best or most important once) and some content about the galery could be a solution.