@East_Cheam_Lad It's basically one of these. The lid doubles up as the cup. Normally used by (steam) train drivers who would store this somewhere hot near the boiler and the tea would stay hot for hours.
Not sure if a bus driver could keep it as hot for as long!
@ruskin147 Our nervous dog does this. We find it helpful to give her an escape route (back door open) and a long lasting treat like a bone to distract her.