I believe the issue is that the grey dock that you're using is not compatible with Google Pixel 6. I don't know how to get a list of docks compatible with Google Pixel 6 though.
Project with a wired dock
For a faster connection when you play games or compete in esports, use a wired connection. Certain wired docking stations are compatible with Pixel phones. On a compatible dock with an ethernet port, you can also connect to LAN.
To set up and project on your Pixel phone, follow the steps that came with your compatible dock. For example:
On your phone, from the Play Store, install the DisplayLink Presenter app.
Tip: When you connect your phone to the docking station, the app doesn’t need to be open.
With a USB-C cable, connect your Pixel phone to your compatible dock.
With an HDMI cable, connect your compatible dock to your monitor or TV.
Plug in your compatible dock's power cable.
Tip: Pixel 3 and later Pixel phones work with the MediaGear USB-C Hub Docking Station (item 853265008171). Other docking stations can also work.