To raise leg for at least hip hight instead of keeping them below horizontal position. Possible are 2 versions of L-sits. In the first version you can place arms in front of your body and move hips back, which sets focus on your front delts or in the 2-nd version, you can move hips forward and lean upper body slightly back, which switches your focus more on your triceps. The version 2 is recommended for further advanced progressions.