Stray demonstrates an experiment in which FOX News headlines are floated into The New York Times website. He asks if they'd be seen as biased if the reader didn't know.
His post attempts to examine how people decide what is biased, and what that means for journalists. Partly he posits that we see bias when we see ourselves as part of a group. To see the journalist as fair-minded, people may need to see that journalist as one of them.
Stray also suggests it would be helpful to frame stories with less partisanship, but his principal suggestion is to play to the sense of identity and encourage the audience to consider itself unified.