A few years ago my local shopping mall, Westfield Glenfield, added some strange shaped things onto the outside of the escalators.  They're see-through and look like they're made of acrylic.  They are about a metre or so in length and near the bottom of each escalator.  They stick out from the side, a bit like a shelf, but they're angled and not flat.

Does anyone know what they things are meant to do?

I thought maybe they were some sort of safety device, but I can't really see how they are meant to work other than maybe stopping people from sitting on the rail and dangling their legs over the edge.

I tried looking online for an image of one so people would know what I'm talking about, but none of the images of escalators that I found on Google have them, maybe they're not used overseas?