That's a pirate flag for those Crossfitters from Philly that tend to like pirates.
Agility Ladder drills for an extended dynamic warm-up.
4 rounds of:
Single Leg Reaches 30sec/30sec
Kettlebell Swings 1 min
Deep In & Outs 1 min
Med Ball Overhead Reverse Lunges 1 min
2 rounds of:
30 seconds at each drill.