In a flashback to 1960 Pennsylvania, Max is shown as a schoolboy with long hair that would have been unthinkable at the time. (Within a few years, the Beatles would shock America with their "long hair," putting an end to the Eisenhower era of crew-cuts and flat-tops.)
During scene in glass sided living room a boom mic is clearly viable above the fathers head reflected in the glass behind him. Two to three shots within sequence.
At 17.50, during the scene in glass-sided living room, a boom mic is clearly visible when reflected in the glass above Max's head.