What activity counts towards "last modified?"

[Brontie Masero]

I want to make a dash card that shows how many cards on my board got a new comment in the last week. Or any activity really, a new comment, movement, complete a checklist item, etc.

I set up a simple dash card that looks at the board it's on, last modified this week, and it found only one card (I know there's been more activity than that). I did a little testing, and a comment on a card didn't affect my dash card. So far, I found that adding/removing a member or moving the card affects it. That's nice, but I need to see comments or checklist activity.

At this point, I'm looking either for a list of activities that "last modified" will track or any ideas someone might have for how I could track comments and checklist activities. Thank you!