The use case is binary file management. Obsidian already supports inline rendering of PDFs, audio and video files. This fact invites such files to become integral part of the vault. However, Obsidian does not support assigning metadata to binary files, like it does for markdown. You cannot tag a PDF, for example. The same goes for canvases, AFAIC.
It is possible to use a “twin” markdown file, and there are plugins that try to automate this, but that is cumbersome.
Now that we have properties and property panes it seems logical to extend property support to binary files. It is clear, though, that properties for binaries would have to be stored externally w.r.t. the file, like in a JSON file inside .obsidian.
Proposed solution
The property pane works for binary files exactly as it does for markdown files.
Current workaround (optional)
Creating markdown files that mirror/link to the binary files.
+1 for this - I’m scanning pages from a paper notebook to bring them into Obsidian as PDF files. And PDF files don’t have Properties so they can’t be linked/tagged/categorized/etc. and can’t show up in the Graph display (aside from disconnected orphan PDFs, unless I create mirror .md files or link directly to the PDF from other notes)