By Alex Lauer “You haven’t used the Mirror yet? Go take a foam roller class right now!” That was my own mother a few months ago when I went over to my parents’ house for Sunday dinner. Well, Sunday snacks, followed by board games, drinks and then dinner, as these things normally go. But instead of plying me with food first upon my arrival, she pointed me into the back hall and into the room with her new Mirror. That’s Mirror, capital “M,” the impossibly chic home fitness machine that’s housed in an actual mirror. If my mom buying one (and subsequently championing it) was the only experience I …