It takes some inspiration from the "alltray" tool (https://alltray.sourceforge.net/, https://linux.die.net/man/1/alltray).
What does it look like?
Screenshot in Kubuntu, using the Qt menu:
$ CMD_TERM="xterm -geometry 80x30 -hold -bg black -fg green -e"
$ traymenu qt --debug \
--submenu "Test/sysinfo" \
--item "disk free: $CMD_TERM df" \
--separator \
--item "mount: $CMD_TERM mount" \
--submenu-end \
--item "uptime: $CMD_TERM uptime"
Help!?
$ traymenu
No arguments
Usage: traymenu qt|gtk [-d|--debug] [ --icon <filename> ]
( --stdin | { --item '<label>: <command>' |
--submenu <label> |
--separator |
--submenu-end } )