Since movie theaters are closed to everyone, I watched a film through the streaming platform of Netflix called Horse Girl (released earlier this year). Sometimes a film is described as "mainstream" to explain its wide-ranging appeal and entertainment value to the largest audience possible. Horse Girl is not one of those films. So far, Jeff Baena has only directed darkly twisted comedies like The Little Hours (2017) and Life After Beth (2014). But Horse Girl is a quiet experimental drama about grief, isolation, and mental illness.