By default, a map's main image/thumbnail is also used as the blurred page background image. With a growing number of maps using posters/graphic titles for the thumbnail, sometimes it is not always the most suitable as a background.
There is now a way to override the page background to be any image you want. Simply insert this line into the page source (anywhere) and put the desired image filename. You don't need to (and shouldn't) put the full URL.
Generic example:
[[include bg-override image=FILENAMEHERE]]
Example from Echoes:
[[include bg-override image=echoes02-2019-09-10-0001.jpg]]
Example from Frightmanor:
[[include bg-override image=8_frightmanor_shot.jpg]]