I don’t think that’s an SD () button, and reading your description initially confused me until I opened the Events tab to see what you were talking about. I think that icon is intended to be like a line chart on a page ( + ) to represent the My Day timeline. That’s what I see when I tap the icon immediately to the left of the . I think the events pulled into that view are all cloud-based and not streamed from individual cameras’ microSD cards.
I understand why someone might think it looks like an SD card, though, especially on a small screen.