The reaction from the audience that we suspect the author intended. We can't really know for certain whether it was intended. It may have been, or it may have been that the author was aiming for something completely different and just missed. We can occasionally get a quote in an interview confirming, or at least claiming, that a specific audience reaction was intended, but usually this term is only useful for fans talking to fans.
To provide a concrete example, normally, the audience hating a character is unintended by the author. But sometimes, because writers want to achieve Emotional Torque, they create a character who hits known markers for a hated character, in order to (pick one):
- Make them a hateable villain so the audience will root for the heroes to defeat this jerk.
- Not hurt what sympathy the audience may have with their killer.
- Make their eventual redemption feel more complete.
- Make it more obvious to the audience why other characters dislike them.
- Provide an outlet for the audience's ire when the real villains are hard to hate.
- Achieve some other artistic effect.
No examples, please. Do not list this on trope descriptions.