To mark a snippet as favorite, simply tap the star on the bottom left corner of the second. Don't worry, we automatically favorite the video you add in a day.
So why select a favorite?
We know not everyone is going to want to mash together all their seconds. So we added the option of a picking "FAVORITES ONLY" or "ALL SNIPPETS" in the mashing screen. When you have "FAVORITES ONLY" selected, we'll mash a video of the seconds you've favorited (starred).
FYI: You can always go back and fave or unfave the second of a day.