On your way to the restrooms inside the Hollywood Brown Derby, you may have noticed an elevator and pondered why it's there. You cannot go in the elevator, but it's actually part of the early history of the Studios.
The elevator is actually one of two ways guests could access the now defunct Catwalk Bar, a cocktail bar located on the catwalks above the area that is now Disney Junior - Live on Stage in Soundstage 5. Alternatively you could take the stairs (which you can sort of see in the photo above) to the left of the elevator. Once up there, guests could order appetizers and light snacks while watching television on a large screen.
Below the Catwalk Bar was a restaurant called the Soundstage Restaurant that changed its theme over the years, but was a table service restaurant.
The Catwalk Bar is no longer in existance, having been removed to make way for Bear and the Big Blue House back in 1998. Interestingly enough, Bear and the Big Blue House replaced the Soundstage Restaurant but the Catwalk Bar remained open between performances until Disney added more performances of Bear and the Big Blue House and decided to remove the Catwalk Bar entirely.
Given that the elevator and staircase are part of the Hollywood Brown Derby's building, it remains a vestige of the former lounge that most guests never knew about.