The seller doesn't need to see photos, but it could be very useful for him to see exactly what you received, as he may prefer to refund you without the need for return (returns for not-as-described are at seller's expense if they want the item back). So there's nothing unusual about such a request - as a seller myself, I too would request photos.
However, you don't have to supply them. All you have to do is read Ebay's Money Back Guarantee, to learn how to open a Not As Described return request or case. It's on every listing, and in various other places across the site. You also have the More Actions dropdown beside the transaction on your Purchase History page, the Resolution Centre (link at foot of any page), and the Help pages to refer to (links at top and foot of any page).
So, with all these tools that Ebay supplies, I'm not sure why you haven't used them...? You haven't supplied any useful information (dates, for example), so it's impossible to accurately advise you. Perhaps you're out of time to open a return request or case (you have 30 days from the delivery estimate on the the order in which to do so)...? Or perhaps you allowed the case or return request to time out...? Or perhaps you purchased on Ebay as a guest, ie. did not open an account, or were not logged into your account at time of purchase..? If any of these apply, Ebay won't be able to help you. You will have to open a case in PayPal (or with your card provider if that is how you paid). You have 180 days from purchase date in which to open a case in PayPal.
@mape_8829
