Even flashing requires a little practice.
Not doubt even the most experienced flashers started
out doing it in front of a mirror. To make sure their
clothes opened as quickly as they needed them too. You're
seeing Liza do a little practice. Warming up for flashing
on the cold snowy winter scene. Only when she feels
comfortable she goes outside to flash. When everything
is ready and she's good to go. She is looking to have
the maximum impact when she flashes. If the guys around
her don't freak out, she doesn't feel like she's done
a good job.