Correct Pieter, not a yacht as you can rent a cabin on board, rather than having to charter the whole boat (that's how we define it here at SuperYacht Times anyway).

No yacht can ever be called a ship !!!

Bob, a 12 person yacht is just a small cruise ship. Only the users of that yachts will pay lots and lots more per cabin as the ship is being advertised as a yacht. So it is marketing. Remember the role of Graham Chapman as Raymond Luxury Yacht, it is all about snobbery.

Ok - now I have changed The Admin Category list for both of the photos of Polarfront. Let's see what happens next.

To confuse you all further, the owner's website refers to her as a yacht

I'd argue that you can put containers on the deck of a tanker but it doesn't make it a containership. DNVGL's class information for "POLARFRONT" I believe, provides the most authoritative type information:
https://vesselregister.dnvgl.com/vesselregister/vesseldetails.html?vesselid=10693

I know, but listed on Shipspotting as Research/survey Vessel.

She is actually a small cruise ship (12 pax) these days: https://www.latitudeblanche.com/?lang=en