A year ago, the world stopped. At least, it felt that way last March to residents of San Francisco, who saw their brimming city hollow out and fill with plywood sheets and proverbial tumbleweeds as some of the country’s strictest shelter-in-place measures went into effect. Lockdown wasn’t just an internal anxiety, it became an aesthetic, a visual language of uncertainty and loss as businesses boarded up or remained closed and shadowed. Also, it was ugly.