File Properties for Imported Objects
A 'Properties' or Meta panel, different from a 'CSS' panel.
This panel would have information on imported or placed files and their attributes.
Files would have their source (src) property, original dimensions, size, etc. Maybe even a little thumbnail.
There would also be a way of changing the linked file, opening source file in associated software etc.
Richard Merrill commented
My developer has to sort through a Subversion repository to find which graphics look like the ones in the XD layout. I haven't found any way to identify those. Adding the file path to the design spec view, would be a big help.