[Time spent in the carnival means that the explanation is good enough for Gottlieb. He was able to (somewhat) get used to talking, walking skeletons - why not robots? Although to be honest, most of his experiences with robots back home were with the electronic appliance variety. Alright, so all of his experiences were like that. One just didn't tend to run into robots when their entire world was a small podunk town in the country. Thus, he looks up and down Mettaton with an expression of wonder and curiosity. At the very least, he notes, he's quite pleasantly shiny.

As is his way, he gives the gentlebot a courtly bow.]

A star, you say? Well, it is a pleasure to meet a celebrity... even if I am not myself familiar with your work. What sort of talent might you be? A musician? A thespian?