The hyperlink simply points to the file to be opened. Which app is selected
depends on the file association on the computer being used (Windows OS).
IOW, if jpegs are set to open in Photoshop that's the app that launches if
the hyperlink points to a jpeg, but if a .tif file is associated with MS
Office Document Imaging that's thte app that launches if the hyperlink
points to a .tif - so any graphic formats would have to be reassociated with
the program of your choice (compatibility assumed). Just keep in mind that
any time you double-click a graphic file it will launch the app it's
associated with.