Moving application-specific icons under the `.../hicolor/48x48/` directory does not work: running `qvm-sync-appmenus` for a fedora-23 template displays:
```
----> Failed to get icon for XXX: No icon received
```
A solution is to move icons under `.../hicolor/48x48/apps/` instead (as suggested by [FreeDesktop's Icon Theme Specification](https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html)). Indeed, there is no icon file directly under `48x48/` in my (very standard) fedora-23 template VM; they are all under `48x48/apps/`.