It will probably confuse you more, but technically, the Glide Slope is considered a navaid too. It is separate from VOR, but for your perspective as a pilot, it uses the same radio, and displays using the same cockpit instrument as ILS. The only time the glideslope needle is deflected (no "off" flag) is when the airplane is receiving a signal from the glideslope transmitter on the ground.The ILS Components
When you fly the ILS, you're really following two signals: a localizer for lateral guidance (VHF); and a glide slope for vertical guidance (UHF). When you tune your Nav. receiver to a localizer frequency a second receiver, the glide-slope receiver, is automatically tuned to its proper frequency. The pairing is automatic.
When he flips the switch to VOR2, and I see the glideslope needle deflect (and based on the direction of deflection of the Localizer/Range needle), I assume he has tuned the ILS frequency into NAV2. He doesn't mention that, and because the video is cut we can't see him doing it, but it's obvious from the indications.