As a musician, when I'm hearing someone perform, I'm listening to the timbres they produce, the technical fluency, the tempo they choose, and whether it is a coherent and persuasive performance. Everything is very analytical.
My question to those who are less/not musically educated: what do you actually listen for? How would you determine if a performance is average, good, amazing, out-of-this-world? Do you tend to look at the performer's body movements?