I feel I've seen that photograph before as I remember the trolley on the deck. I probably have a digital version of it in my Olympic collection somewhere, which I still haven't sorted out :-)
I wonder how many prints they made of it?
Anyway, just after the auction ended I decided to write a private message to the seller, politely stating that the ship was the Olympic and pointing out the WSL pier that can clearly be seen on the left. I shan't quote his response but I was surprised that he chose to contradict me and stating that certificate "proved" it was the Titanic, and directed me to the issuers of the certificate. I was going to respond, but then thought the better of it.
It does seem that when it comes to Titanic memorabilia, what people want to believe is often more important that what may actually be true.