You have to open the device to make a call. In android theres an external button which can be used to answer, but currently non functional in SFOS.
Can of course answer with BT headset, possibly make calls too if you have a smarter headset than I do.

That reminds me, it does not connect to my (older Land Rover) car BT eitherm but I expected that as the same happened with the X using the community builds.

The Gemini opens like a regular laptop, it does not flip around to give a tablet form factor.