Most directors have their own unique fingerprint. Their films reflect their own unique artistic sensibilities and creative visions. And over the course of a career, it's easy to see certain patterns form in their work, whether it be a repeated visual aesthetic or the inclusion of very specific types of characters.
Some auteurs are able to sustain long and fruitful careers without ever diverging from their self-created molds. Woody Allen has been making the same kinds of movies for the better part of four decades. Same goes for Martin Scorsese. And we all pretty much know what to expect from a Quentin Tarantino movie by now.
This can naturally lead to pigeonholing, and sets up unreasonable audience expectations that can suffocate a filmmaker. After all, just because you do one thing very well, that doesn't mean you can't try something else.
And that's why even the most steadfast auteurs have to occasionally shun expectations, throw caution to the wind, and deviate from their normal directorial habits for a bit. Even if it's just for a single film.
The results aren't always pretty. But at least they were willing to try something different.