How do I tell if my shell is being run from within Dolphin's integrated terminal?

I'd like to choose whether or not to load zsh plugins if the shell is, at the moment, being run within Dolphin. Is this possible? I've considered: - ps: ps, at least without any flags, does not seem to offer useful information - xdotool: xdotool can search for a window named Dolphin, but I don't think that it reports on the current window - environment variables: there are some env vars set up for Konsole in general ($KONSOLE_DBUS_SESSION, etc), but none for Dolphin