Why would you want to see pictures of the messy spare room? LOL.
Basically, it's simply taking an instant picture of a slide.
You put a slide in the unit and press a button. A shutter opens and a strobe (flash) fires, projecting the slide onto instant film (obviously a lens is involved). Then pull out the photo as you would any pack-film camera.
Here's a video of a Vivitar unit (I have one) but it doesn't show her actually using it:
https://www.youtube.com/watch?v=_UrZictx60o
The vivitar has three color filter sliders.
Here are a couple pages for the Polaprinter:
http://www.filmwasters.com/forum/index.php?topic=2693.0
http://filmphotographyproject.com/c...k-tastic-print-your-slides-polaroid-pack-film
The polaprinter has brightness and contrast dials.
There are also the Daylab units:
https://www.youtube.com/watch?v=uO-sv_ncUXk
https://www.youtube.com/watch?v=9xGBY4_cVmU
The Impossible Project's Instant Lab is similar in concept.
Now, I think I know what you're thinking... I'm sure you could use an enlarger to expose on a pack-film back. This might allow a bit more control than the dedicated units, but you're stuck with existing instant film sizes. It might not be worth the hassle, unless you want to enlarge a crop (croplarging?).