Okay, so I did some more experimentation, and I found that changing the resolution in GIMP to match my monitors resolution made the image display in lightDM. Could this be a problem with LightDM being unable to handle non-default images that are not the same resolution as the monitor?
Okay, so I did some more experimentation, and I found that changing the resolution in GIMP to match my monitors resolution made the image display in lightDM. Could this be a problem with LightDM being unable to handle non-default images that are not the same resolution as the monitor?