I want the header of the Twenty Eleven theme to be a random picture that I've already uploaded for this purpose. In my Media Library, I see several images that have the "Header Image" label next to them. However, when I go to Appearance > Header and select "Random", only the default images get cycled through.
In this same section, if I select "Choose Media," I get a list of images with only the option to "Show" on the right. By clicking on that, I get the option to "Set as Header" but that only sets one image as permanent header. Doing that and then selecting Random doesn't do anything.
Any ideas why this is happening?