Gtk standalone application (PackageCompiler) cannot open images

I have this Gkt.jl application, and I’m trying to make it stand-alone with PackageCompiler.

Right now most functionality seems to work, although I have this problem at startup, when I try to load some images, which do not show up.

(AccerionCalibrate:493): Gtk-WARNING **: 15:20:13.141: Could not load image 'logo.png': Couldn’t recognize the image file format for file “/home/nicolau/MyProject.jl/logo.png”

(AccerionCalibrate:493): Gtk-WARNING **: 15:20:13.209: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.

Could this be related to some package missing from the sysimage?