In LibO you can create your own gallery and add there images. There are a lot of different images files possible, but NOT odg the file of LibreOffice draw, so it's not possible to add to an gallery single .odg files. You can move shapes from LibreOffice Draw to an gallery (via click shape group and move the group to the gallery). Than this shape group was stored .sdg .sdv and .thm. The problem is that you can't easy change the content within this 3 files. If you save each gallery item at an .odg file you can update every single file easy. svg for example is available. Please make the standard LibreOffice Draw file type available in Gallery.
The binary gallery files are build with the compilation. You have to submit "raw" drawings such as png or svg and create a makefile as described in extras/REAME. That's not a bug neither we should introduce another binary format for shipping.
Created attachment 153424 [details] Add Image to gallery sorry heiko but you get me wrong. this is not a bug of how to add odg files into core/extra/gallery/... ok there it's also an problem, but the main issue is, that you can add all kind of image files to an gallery, but not the LibO drawing file format odg.
The file list shows a filter for various kind of raster and vector graphics. ODG is a binary document file for text, format, drawings, images etc. stored together. There is no sane way to extract only a few information, meaning standard shapes, from this file and ignore the rest.
*** Bug 147346 has been marked as a duplicate of this bug. ***