Anonymous
No “broken, or missing icons” are evident in your screencaps.
(late edit: yes, I now understand: missing for the “Themes” and “Logout…” submenu items)
For some of the top-level menu entries, and some of the submenu items (both “category” and “item” entries)
iceWM is hardcoded to display a “diamond” glyph (indicating currently-selected, or recently selected) or None.
Within your ~/.icewm/menu file, notice that only a subset of items represented in the menu are modifiable.
iceWM builds the overall menu by applying wrapper which is comprised of a set of hardcoded items+rules.
Expanding on what masnick mentioned, if you do encounter a “missing” icon after installing a given app:
1) visit /usr/share/appications to verify the installation package did (or did not) install a .desktop file
2) if unsure, as in, not all the names of .desktop files EXACTLY match their corresponding program name, you can skim view the “Installed Files List” in synaptic for the recently-installed package or, via commandline: dpkg-query -L <packagename>
3) if a .desktop file is present but a corresponding menu entry is absent, open the .desktop file in an editor and check/remove any limiting declarations, e.g. “OnlyShowIn=Gnome”, “Hidden=True”. After editing/saving, perform an “Update Menus” operation (and/or desktop session logout/login) then recheck whether the expected item is now correctly displayed.
A full explanation of “what each line means, withing a .desktop file” is available here: desktop-entry-spec-latest.html