Those items in the context menus are actually not commands, they just happen to call the same code.
Commands themselves can have icons, but most community plugins probably don’t specify those, but only specify a icon when adding to the menu’s.
Some plugins do, for the toolbar on mobile.(this is also the only place where command icons show up in the core app)
So most commands will probably have no icon if this gets added, either in core, or a community plugin.