Darren Carver-Balsiger’s review published on Letterboxd:
A perfectly constructed structureless masterpiece, Mirror is both indescribable and essentially plotless. Yet it is this lack of adherence to any firm rules that makes Mirror so tantalising. Each scene connects not via chronology or logic but by pure abstraction, linking together by ideas and emotional connections. This captures how our memories and dreams work, the lack of any kind of narrative is the form we see the world in, even if our curiosity leads us wanting stories. By providing no firm story, Mirror is distancing, but its sheer humanity makes it engrossing. This is a work so personal to Andrei Tarkovsky that we sense it to be a life we can never have had, but it causes us to reflect upon our own lives, particularly our own mortality and maternal bonds. Maternity itself seems to be the key theme in Mirror and, throughout all the imagery and plotless moments, it is the love of, and for, a mother that remains firm and true. Mirror is a film about absolutely nothing except images that may or may not mean anything, but by being so meandering it shows us the moments that make up a life and however shallow they each may be, together they form everything we have. A truly beautiful cinematic poem.