The Reef used to be a frequently used structure, specifically made for the use of Pearl creation, repair, and modification. The structure is equipped with an Artificial Intelligence named Shell, which assists the user in activating the building's functions.
The Reef has an ocean motif. The building is shaped like a clamshell and it is located on an island in the middle of an ocean. Outside the building's door is a bridge, that connects the island to an unknown piece of land. On the inside, it includes, but is not limited to, an activation room (as shown when Steven places his hand on a Gem Pedestal), a Pearl "remodeling" room, and a Pearl repair room.
Shell, The Reef's built-in A.I., is a helpful guide that makes suggestions as visitors travel throughout the structure. After Pearl and Pink Pearl's argument and Steven's outburst, Shell decides that the two Pearls are far too "broken" to be repaired and require rejuvenation, trapping them in a shell and sending shockwaves throughout their bodies. This leads to the two having a heart-to-heart and Pink Pearl acknowledging her trauma; this combined with the attempted rejuvenation causes them to fuse into Mega Pearl. Shell is voiced by Deedee Magno-Hall.
- Although it is never stated within the show, Rebecca Sugar has gone on record to state "our Pearl never belonged to White, but White is involved of Pearls in general, so there is a connection, and that’s all I can really say at the moment" at SDCC 2019. This implies that White Diamond is directly involved with the creation of Pearls.
- The clamshell-like design of the building and the fact that it is surrounded by ocean mirrors how Pearls are created in real life (from oysters found in the ocean).
- The seemingly peaceful A.I. that turns out to be "evil and murderous" in the end, along with the walls forming in the objectification hallway and Mega Pearl having to create a series of "holes" on said walls for Steven to pass through, maybe a reference to the video game Portal. This is further evidenced by the fact that Shell's name is extremely similar to that of the protagonist of Portal, Chell.
- The overall interior design of the building is a homage to the Art Nouveau style of architecture, which was the prevailing movement of applied arts during the late 1800s to 1910s and is characterized by the use of organic forms, most notably sinuous lines (also known as Whiplash Curves) to create elaborate and intricate designs that mimic nature. Specifically, the interior design of the building takes inspiration from Casa Batlló, a residential apartment designed by Catalan Modernisme architect Antoni Gaudí.
- The planet the Reef is located nearby may possibly be Saturn, as Jupiter is seen just before arrival at the Reef, and a gas giant with a large ring can be seen in the background. Additionally, this could mean that the "planet" the Reef is located on could be Titan, one of Saturn's moons which has an ocean.