The first file is millenium_front.ham. As the name indicates, this is a front-view of the Millenium Falcon in HAM format. This file was part of a disk bundled with the 96 edition of the Amiga Plus magazine. What is cool, is that the library found the following version string: Written by ASDG’s Art Department Professional IFF3.0.4 (31.03.95) embedded within the file. So we are decoding a file from 27 years ago.
The second file girl pic is, indeed, a picture of a girl, and was part of the tutorial for some morphing software, TSMorph. Here again, the library found some annotation, but it is not really useful: Written by HamLab Plus 2.0.8. As the picture is a 4 bit deep grayscale image, I doubt HAM encoding was really needed. From the pattern of the picture, I would say it was digitised from a newspaper. This picture was a good test because 4 bit grayscale is not a typical Amiga depth, more a Macintosh page layout thing.
The next file has most certainly bogus meta-data: I highly doubt that Darkside.iff by Jogi, was created on the 27th of February 1980, as the Amiga computer came into existence, and no computer of the early 80s could handle a 640 × 480 bitmap. This is typical of the demo graphics from the early 90s, I would say.
The following image is one I remember, Color-Lady was probably used in some advertisement. And with that kind of makeup, I’m pretty confident this image is from the 80s. Thanks to HAM (Hold and Modify) it has a large numbers of colours.
Finally, Welter 04 is a pretty nice spaceship / science-fiction scene, I would say this is not some digitised photograph, but a hand-crafted pixmap. This one uses a fixed, 8 bit palette.