In the first image, I don't have a link to the page with that block, but I can assume it's a "Post Feed Block" type? Post feeds are just display posts and comments the way It's display in the Demo
Post blocks usually display "Just Posts", which means you may see your latest 5 posts of your community, all of them submitted in one Topic.
However, What I see in second image, It's NOt a Post Feed block at all! It's a "Topic Feed Block". again i have no idea and i need links to investigate first, but if you want a Topic Feed block the way in Demo site:
For create a block like that, you simply need to create a block as "Topic feed", instead of "Post feed".