Well, the seller doesn't have any feedback yet,
so it's hard to say how good/bad of this seller 
is.

On the other hand, it's not surprising to
see the similar looking cels.  Remember that one
sequence of animation can often have 10 to 20 cels 
easily.  If this is a A-1 cel, the other 
collectors may have the A-2 or A-3 cels which can 
look almost exactly the same.

The seller' other two auctions look okay to me, so 
I think the seller is fine.