I'm not familiar that particular image file format, but I know that to send a file from iTunes all one has to do is:
1. After clicking on the appropriate file, simultaneously press command, shift, and the letter R, to show the file's location in Finder. (Alternatively, the file can be right-clicked, and "show in Finder" selected from the menu.)
2. Right click on the file, and from the menu select "open with -> other -> utilities -> Bluetooth File Exchange."
From there simply follow the normal procedure to connect to a device and transfer the file.