Good question! If you are worried about this or fear it’s happening you can consider adding a watermark with your company name or logo on your images to protect them. If you decide it’s worth it you can also message the person and simply ask them not to represent your work as their own. But truthfully this is not a common problem we have run into. Passing off other’s work as your own will only cause problems in the long run as the client will soon realize that your abilities and what you have shown as your work don’t match.