From This Land Wiki
Here's the useful bit that's on the Special:Upload page but not the File:File.jpg page.
To include a file in a page, use a link in one of the following forms:
[[File:File.jpg]]to use the full version of the file
[[File:File.png|200px|thumb|right|alt text]]to use a 200 pixel wide rendition in a box in the right margin with "alt text" as description