Bruce Beveridge's book, vol. 1, p. 385, has a photo of the type of electric panel shown on the right-hand side of the door. He identifies it as a stateroom light switch and call panel. The top device is an electric outlet (receptacle). The other devices are light switches and a call button for the cabin steward. From the appointments shown in your photo, this would be a first-class stateroom.
The electrical “convenience” outlets found on the Titanic were used for table/Gimbal lamps, portable fans, and bed warmers in the first class staterooms and suites at 100vdc. They may also have been found elsewhere on the ship, such as in the kitchen, for the brand new electrical appliances such as meat slicers, peelers, and food processing type devices that were in use there. They were of the pre-BS 73 type, the “standard” 5A 2 round pin that were used in Britain (at 220-240v) at the time.