Unexpted Stephen Maturin?

Am off to Munich for the weekend - and on Monday I'm going to Colmar (but it will involve looking at mediaeval paintings, so that's work - right?)

I posted a whole lot of cards, including most of the lj ones. Apologies for the lack of stamps - I took them to the post office in the hope of getting nice stamps, instead of the horrid ones from the machines, but before I had a chance to object, the girl behind the counter stuck what look like parcel labels on them. Bah.

I keep walking past a poster for a talk by the forensic entomologist Mark Benecke, who I've just googled and who appears to have a fine conceit of himself, judging by his website.

However, that's not the point: the point being that the poster's photo - which is here, in a slightly differently cropped form, keeps making me think "...Stephen Maturin?", despite the fact that a second inspection shows that he's wearing a modern and probably very expensive trekking shirt. But there's just something very Stephenish about it somehow. Though I don't think Stephen would be conceited or humourless enough to describe himself as "The Lord of the Maggots"....

Query

So what do you call images that change as you walk past them? I've seen nineteenth century ones recently that were made by cutting one picture into equal strips and pasting it onto another image at right angles, so I'm not sure if 'hologram' is right.

Oddly enough, I need to know the proper term for this for an argument in the latest bit of my thesis...