Earlier quoted context omitted.
Feedback is a response to an input. Okay, sure, clicking the remote to turn on a TV and selecting a channel is input. So, by a stretch, we can call the four hour binge a kind of feedback generated by two button clicks. Sometimes people get glued by a screen that they did not turn on; is that still feedback? E.g. kids watching a screen in some waiting room at a children's dentist.
I think we can talk about feedback without input, yes. The reality of feedback is actually very broad. If we just look at the world of video games, and consider all the different types that exist, there is a wide variety of feedback, some more or less tied to input. In some cases, like narrative games, the feedback is much less connected to the input than in a fast-paced FPS, for example.
E.g. suppose the subject is watching a game show. They get internally involved, within their mind, by trying to guess an answer before the contestant does and then fist pump when they get it. When watching a crime story, they try to guess whodunit. That sort of thing.
There can definitely be a sense of working toward a reward.