For example I only want the cover art as my image. Not a 3D-rendered box, not the composite screenshot with box and wheel art, just the flat 2D cover art. So I point my config.ini at a custom artwork-cover.xml and that looks like:
<?xml version="1.0" encoding="UTF-8"?>
<artwork>
<output type="screenshot" resource="cover"/>
<output type="marquee" resource="wheel"/>
</artwork>
Note, the output uses type="screenshot" resource="cover". This still puts the image in the "screenshots" folder; that's just how it works. Whatever you define as "screenshot," that's what gets put in the gamelist <image> tag. (Again, this for ES, I don't know how it might be different for Pegasus FE.) But I use the "cover" resource and so the image that appears in my gamelist is a picture of the cover, not a screenshot, even though it's called "screenshot."
If you want raw cover, screenshot, wheel and marquee outputs, use artwork.xml.example2:
<?xml version="1.0" encoding="UTF-8"?>
<!-- This example simply exports the raw unedited versions of each artwork type coming directly from the scraping source -->
<artwork>
<output type="cover"/>
<output type="screenshot"/>
<output type="wheel"/>
<output type="marquee"/>
</artwork>
The default artwork.xml only outputs two images, but one of them has many layers, and between them it uses three of the four resources (the "marquee" resource is not used. Note that even in the output node called "marquee," it uses the "wheel" resource instead):
<?xml version="1.0" encoding="UTF-8"?>
<!-- This is the default artwork.xml provided by Skyscraper. More examples can be found in '~/.skyscraper'. Be sure to check the full artwork documentation here: https://github.com/muldjord/skyscraper/blob/master/docs/ARTWORK.md -->
<artwork>
<output type="screenshot" width="640" height="480">
<layer resource="screenshot" x="20" width="520" height="390" align="center" valign="middle">
<rounded radius="10"/>
<stroke width="5"/>
</layer>
<layer resource="cover" height="250" x="0" y="-10" valign="bottom">
<gamebox side="wheel" rotate="90"/>
<shadow distance="5" softness="5" opacity="70"/>
</layer>
<layer resource="wheel" width="250" x="-10" align="right">
<shadow distance="5" softness="5" opacity="70"/>
</layer>
</output>
<output type="marquee" resource="wheel"/>
</artwork>
