My brain wants/expects to (on mobile) swipe (back and forth, horizontally) or (on desktop) click (as a series of slides) among these 3 cards.
And (as an admin) I always want things that are clickable to be optionally hoverable.
And, in the composer, a way to designate any list of internal links (but just the content area of Topics and Posts) to be displayed in sequential order as a series of slides (appearing both inline and pop up) just as we already create inline image slideshows.