How do I set up a pivot table, so by default the rows are collapsed?
You have to manually collapse them while you are in Analyzer. Once you save it in Analyzer with them collapsed, they will be collapsed for the card viewer.
thanks @MarkSnodgrass what happens when new rows (values) are pulled in. Do I have to go back in and manually collapse them as well?
I only have a couple cards where I have this set up, so I can't say with 100% certainty, but I think you will have to go in and collapse those. Would definitely be something to monitor after you initially roll it out.
As an alternative, you can have your main card be the summary totals, and then make a drill path on the main card to show the details. Then, you wouldn't have to worry about the expand/collapse functionality.
New values would need to be manually collapsed. I'd recommend adding an idea to the idea exchange to allow a setting so that all groups start collapsed as doing this manually for many different rows can be tedious.