@Sene86  
Now that’s paying attention to detail.

One is male and one is female I would assume. Given the general gender ratio in Equestria (I think this is still set in Equestria anyway) I would say the moons are the female restrooms and the star is the male. Just a guess though.

sighs It’s a reference to real world out houses during the olden days. The crecent moons meant for women and the stars were for men.

@Delzepp  
following the logic of previous posts…you only shit at night I guess

@Twilatron217  
but both the moon and the stars are at night…

@Twilatron217  
oh my goodness XD

You shit in one during the day and you shit in one during the night