No clue, but when my DD was that age, the toilets at the airport that had the plastic covers freaked her out. The ones were you push a button and the plastic cover moves to give you a "sanitary" surface to sit on. I remember being in O'hare and DD was freaking out horribly. And one of the women who was cleaning the bathroom just tore the plastic wrapper off so DD could sit on the potty in peace. It's so hard when something freaks out your newly potty trained child in the bathroom.
DD (3/06)
DS1 (7/09)
DS2 (8/13)