How do I educate user about new kind of visual calling technology?

I am working on web platform. Bascially it is a visual calling solution. Like intercom chat our client can place our call button on their website and their potential customer can make call from that button. (internet based call no need of software). Now the twist, well this is neither video call nor screensharing, in this via browser both users are connected and all the information material like 360 virtual tour, video, brochure will be shown to both like live ppt presentation but over internet call. Unlike screensharing content will be adaptable to viewer's screen and will be interactable from both sides, also unlike team viewer where things actually happen in host's computer. Here content will be smae both side just interactable and if one person does something it will reflact on another person like screensharing.

Now I am having hard time making the graphic for it and educating customer on intial screen before call.

Many people think it is video call. what shall i do.