It's not the fact of them watching, I would watch also and when I am warming the team up I employ my wife to go watch the other team and give me a scouting report. It's the fact how they were standing with their arms crossed and just laser focused and in my opinion intimidating my DD.
We ended up losing 5-2. We beat the same team 6-1 in the fall, my DD had 10 Ks in that game.