The mirrors are covered so the women will spend more time paying attention and less time primping in the mirror.
Never stopped them though, most just pull out their compacts and touch-up their make-up in their seats. You can time it like clockwork...before a trip to the restroom, before the lunch break, before the session ends, before any assignment you may have (watching contribution boxes etc) ...because you never know when the super bethelite elder with goals of going to gilead and plans to be of the anointed is going to come around the corner and sweep you off your feet