When Al is measuring the first woman's foot, her foot is completely in the shoe sizing device. In the next shot, Al is placing her foot into the device again.
When Kelly escapes from the shoe store she uses a key to unlock the door. She then locks the door with the same key from the outside. Assuming this is the only way in and out of the shoe store, unless Al has another key, everyone inside would be locked in and unable to get out of the shoe store.
At about 21:35, as Kelly is leaving the shoe store, the door says "PULL" but she pushes the door open to leave.