The Parchment Inform template assumes that it will only be used for Z-Machine games. For Glulx you’ll have to include more files, such as glkote.min.js, and edit the (manifest).txt file so that the new files are listed at the end of the manifest. The files are in the lib folder of Parchment’s source code.
It might be easier to update Quixe instead, if I recall correctly the version of Quixe that comes with the Inform 7 installation doesn’t support pictures, but the latest version does.