All other emotions only distract and lower the quality of the performance. The notion that the performer has to go through different feelings when playing is a layman's superstition.
The idea that the pianist should show to the audience the emotions the music is supposed to portray through his body movement is laughable. I for one have little patience with pianists looking to the ceiling when the music goes lyrical, or something I see a lot in women pianists (but never in men) which is to move their elbows up and down as if flapping wings, as their fingers press the keys. Needless to say these movements are completely unnecessary for the purpose of sound production and should be avoided. Besides it makes the pianist look really silly.
For instance, Glenn Gould’s and Claudio Arrau’s habit of doing vibratos on the keys. You would imagine that they should know better. Did they actually believe they were playing a violin or a cello?
The worst: Lang Lang. My sister burst out laughing when he saw him perform for the first time.
I suppose Jazz pianists can get away with it a lot more. They can sing and everything. Like Fats Waller.