In more recent versions of Defold we identify all of the meshes in the model and let the developer assign different materials to each. The default probably comes from the model itself, or possible if it is unnamed.
We need to update the documentation though. Ping @Pawel
Yes, all the materials defined in the source file are listed there with their names as in the file (e.g. In gltf files you can open it in text editor and search for material, there will be at least one material with name e.g. “default”).
If some file will have more than one files, then for all of them, you will see a property with its name and you will be able to assign a material (and then corresponding to the material textures).
The documentation though should be updated, but screenshot will always show a name from a currently used resource file, so sometimes it still might be misleading, if you use a different file, but we can add an explanation
Maybe it could show a text like “Material: {material_name}” instead of just the name. So the user understand it is some material property in the mesh…