The article was basically about this ("So I began to take note each time I experienced a little hit of outrage or condescension or envy during a Twitter session

The article was basically about this ("So I began to take note each time I experienced a little hit of outrage or condescension or envy during a Twitter session. What I found was that nearly every time I felt one of these negative emotions, it was triggered by a retweet."), and in my experience this is largely how the "mute" functionality is used: literally to protect yourself from experiencing the learned emotional trigger associated with seeing specific keywords or phrases.