/usr/share/app-install/desktop/mirage:mirage.desktop is in app-install-data 15.10.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | [Desktop Entry]
X-AppInstall-Package=mirage
X-AppInstall-Popcon=81
X-AppInstall-Section=universe
Name=Mirage
Comment=A fast GTK+ Image Viewer
Exec=mirage %f
Terminal=false
Type=Application
Icon=mirage
Keywords=Image;Viewer;Graphical;
Categories=GTK;Graphics;2DGraphics;Viewer;
MimeType=image/bmp;image/gif;image/jpeg;image/jpg;image/pjpeg;image/png;image/tiff;image/x-bmp;image/x-pcx;image/x-png;image/x-portable-anymap;image/x-portable-bitmap;image/x-portable-graymap;image/x-portable-pixmap;image/x-sun-raster;image/x-tga;image/x-xbitmap;image/x-xpixmap;image/svg+xml;
X-Ubuntu-Gettext-Domain=app-install-data
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