The fact that they would deface the image with a watermark tells me a great deal about the values of the "museum".

It would be cool if it actually worked like that (as a low resolution preview of things you can get on the actual museum website) - in this case the one offered on the museum website appears to be identical. Same low resolution, same watermark. Perhaps they could save people time by tagging entries that they had already received in low or watermark damaged quality so they could be filtered out of the search.

As I wrote, "Some have them, some do not."

There are lots of possible obstacles to showing high resolution digitizations.

Yes. I'm just noting as currently implemented, it's not very usable. If they had filtering for the low quality trash, it'd be more useful.