Sheer Gym Etiquette: Mind the Mirror
To the untrained eye (or to people who say things like "lunk alarm"), the mirrors in the gym may look like nothing more than an ego boost for meatheads. In reality, mirrors are used to ensure that you are practicing good exercise form. With that in mind, don't get in people's way!
Unless you have a partner, coach, or trainer that is watching your exercise form, it can be tough to simply "feel" whether you are doing each exercise correctly, especially as you get more tired during your long workouts. Try not to get in people's way when they're using the mirror to make sure they're exercising safely. Even for the people who are simply flexing, they may be practicing for an upcoming competition; if it was you, you probably wouldn't appreciate it either.