The inside of a commercial airplane in 1930. Under the ripping panel it says:
"In case of emergency, pull ring sharply."
The ripping panel tore away from around the window, allowing the window to be removed or folded down, allowing the passengers to exit in an emergency. If you zoom in on the windows, you'll notice a loop of material above each window.
The aircraft is an Imperial Airlines biplane called Handley Page W10 (swipe left to see its exterior). The first prototype was built in 1919 and it started commercial flights in the early 1920s until it was retired in 1934. The aircraft had an enclosed cabin that fit 12 passengers and two crew members in an open cockpit. It was also the first airliner to have a bathroom onboard.