It turns out that you can’t post photos through the Hootsuite bulk upload, boo hoo!
Well actually, you can, but in a very roundabout way: you have to first have your photos hosted somewhere else – your own server, instagram, owl.ly, etc. – and then you have to add the image url to each line of your file. Doesn’t sound too bad, eh? BUT, if you’re posting said photos to Facebook you’ll have to go in and edit every scheduled post that you just bulk-uploaded and set the preview to the proper image. Ever lame!
Sounds to me like it would just be simpler, albeit longer, to schedule each image one by one.