Despite of the freedesktop.org efforts to standardize how applications should be integrated into a GNU/Linux desktop environment (DE no on) we can appreciate that in the end they do as they please. Take by example issue #653, and there are many other cases.
Also different DE then to have a different workflow on how applications are fetched, or how to notify updates to the user or how to perform security checks on the fresh downloaded binaries.
Therefore I would like to purpose tow things:
1rs - AppimageKit (libappimage) should only be responsible of providing the means to access the required information about appimages to integrate them into the different desktop environments.
2nd - Desktop integration of appimages should be implemented in a desktop specific way, preferably by the DE development team.
This will allow us to have a better (or perfect) desktop integration and for the AppImageKit development team to focus on making Appimage better (instead of guessing why a icons are not shown in a given DE by example).