Performance pair programming is when one developer drives the entire implementation while the other watches. It is as if someone is solo programming with an audience. The performer prefers accomplishing a task more than taking advantage of the teaching opportunity.
When this occurs, there is no collaboration or discussion about how to proceed. Questions that the watcher asks are often ignored. Typically the Performer is unaware that their pair is not learning anything.
Since one of the most effective learning technique is “learn by doing,” the pair is missing a great learning opportunity.