Hi, @Kenweiland ,
If you double-click on the item and wait for a minute or so, does the photo load up? Note that to preserve your PC's storage, the files in Dropbox will be in "online only" mode, when you tries to open it, then Dropbox will start to download it.
If it still doesn't work, you may want to check if Dropbox is running correctly by checking your PC's tray for the Dropbox icon.
Cheers
Vicker