Just as pop-up mechanisms have many variations, they may also have a variety of different names. This page covers a type of mechanism called a dissolve, a window blinds mechanisms, or a changing-picture pull tab. These mechanisms can be flat, such as in the first two examples, or they can stand up like venetian blinds. There is also a revolving style called a volvelle, which will be covered on a different page (when it is typed up). A similar effect can also be achieved with transparent plastic.
A brief video of a diagonal changing picture card tutorial by DIY Blaster. This is concise, but doesn't go into much depth.
A longer video by Duncan Birmingham of the same style of dissolve, but with much more detail on how to make the mechanism.
A second video by Duncan Birmingham on a different style of a flat dissolve mechanism. This style is a bit more involved than the first type, but it can look more seamless since all the cuts through the image are parallel.
An example of the venetian-blinds style dissolve by Paper Paul. This is part of his pop-up memes series, and shows Jim Halpert from the show The Office looking through window blinds.
Another video by Duncan Birmingham, this one shows how to construct the venetian-blinds style dissolve.
