Neither "Read Only" nor "Player Module" was selected, Images/Maps was selected in the export window.
The image was pushed to the players using "Share sheet" (some images were preloaded).
I was able to see the image using a second instance (even using the alias), four players were not able to see the image. I created an empty campaign with only the exported module loaded but it didn't make a difference. Only copying the images into the directory worked (there were no portraits indicating who could see the image however as far as I remember but I could be wrong).
Players reported they "could not see" the image, I'd have to ask what specifically was displayed.