The two giant non-inflated Santas have been lying on the ground for at least a week. I thought they were about to be inflated when I first saw them, but they stayed on the ground. Later I discovered that they are inflated (and illuminated) at night.
Press the green button. ONLY ONCE - they don't like it if you get impatient. You don't hear anything from outside (although the buzzer is very loud inside) so you wonder if it is even working. Wait for someone to open the door.