Opening a door is actually a complicated operation, as the laborious manoeuvre performed by the ugly quadruped of a robot shows. They could have given it some sort of head to 'humanize' it: a grinning clown, for instance...
Imagine arriving at a company's operations centre and having a thing like that opening the door for you -- unexpectedly? They'll have to call the Nurse Robot and the Doctor Robot and the Ambulance Robot in the wake of your heart attack...
First they could play chess, then they could dance around (on wheels) and balance on one foot, but the latest robot from Boston Dynamics can actually