Does marking a model or show with a favorite heart increase the times you'll see her in the show rotation?

And if not how does that work?.

Is it just better to make a playlist?

I don't know how this helps me in my Collection.
I just see hearts on some cards between others. I can't see only them or only without them.
Favorite works only for Models category, not for Collection category.

Favorite does work for individual cards in the collection.
Within the collection, not a specific card, just hover the mouse over any card.
Then see the heart symbol top right corner.
Click that and you have a favorite card.
Automatically this is added to the favorites playlist.
Simply click my playlists, then favorite. There you will see all cards marked as favorite, and this list can be added to the queue. Open the favorites and click on start to begin playing all favorited cards.