"Steam API failed to initialize. Workshop subscribed items will not be available."

[Vale]

The mod launcher has a space for an associated image. I tried having a line in hpc file along the lines of Image='Filename', and also tried just sitting an image entitled image in the mod folder with no success. For future reference, has anyone figured out how to add one? Could be useful to know, and add to the wiki page because someone else will at some point ask.