Try now. I tried several times with different types of content/apps displayed, to no avail. It analyzes the screen and tells me whatever Gemini would say, instead of actually doing it.

I just tried it now, it worked. Specifically, I long-pressed the home button to pull up Gemini, pressed the "+" to add screen content, and said "add this event to my Google calendar". Confirmed it worked by opening my Google calendar.