Another special feature in culling projects is the use of favorites.
In the display for a sub-collection of the culling project (people, content, similarity, etc.), the photos are combined into groups. You can mark one or more groups that are particularly interesting for the selection as favorites by right-clicking on them. A heart symbol will appear in the display to indicate this.

You can now select "Favorites" as a sort criterion in the sorting so that the favorites appear at the top of the display.
The favorites also play a special role in the smart selection.
If you have marked one or more groups as favorites and then start the smart selection again, the selection of photos is limited to the groups that are marked as favorites. The remaining groups in the respective sub-collection are not taken into account.
If no favorite is marked in a sub-collection, all groups are taken into account for the smart selection as usual.