Skybox

* See also SkyboxGenerator
* See also Graphics_and_Rendering
* See also Windows and Undersea_Windows
A Static Background wrap-around picture used in games.
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A "Skybox" ( alternately 'Skydome' - IF it has more sides than a 'box' ) is a way in games to help illustrate an outside area, usually giving an intended View to the Horizon, and upwards into the 'Sky' -- A background wrapping around the whole visible scene.  The static texture is composed so that when drawn to look seamless, eliminating the corner distortions. It is also low impact on the Client machine Graphics scene rendering. 
A "Skybox" is usually a set of textures made into a box with 4 flat sides and top/bottom, created in such a way that when looked at from a within a limited viewpoint area it looks like an extended '3D' view surrounding the viewer. Often additional semi-3D objects ( like the caricature building fronts, signs ) are added 'closer' within the box. Other true '3D' objects can be placed in the foreground, those which would be viewed from sufficiently different angles.
In BS1/BS2, Unfortunately, the same texture was frequently used repeatedly (some are even at 2 opposite sides seen out windows of a building/level, and some levels actually reuse exactly the same static flat texture 4 times ( ex- on all 4 Compass point window views ). Generally the outside water views in BioShock had little to do with Player activities, so the reuse was of little impact ( and saved on their limited graphics memory 'budget' ).
IN THE MMORPG
Because in the Rapture Reborn MMORPG the appearances of the terrain can CHANGE as the Players repair and add things over time, a system using Cached Skyboxes would get rebuilt periodically ( some automatic mechanism and distribution to the Player's Client Asset Cache ). Actual 'building' Assets and other props would then be situated/placed in '3D' ( though depending on their distance they may be rendered in a simplified LOD form. )
In the Solo BioShock games the Skybox views were often repeated/reused on different levels, and the same ones were reused when you looked out opposite facing windows of the same building. But NOT in the MMORPG, Cached Skybox views would be there matching each of the different near-current views out of all building windows. 
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You Can Still F*ck Up something as Simple as a Skybox :
Unless this is some strange Dada-esqueDada - https://www.thoughtco.com/what-is-dada-182380 artwork, there is a slight problem with that upper track crossing the lower for which the Skybox artist kindof made a mistake. Hint - How low does a AE traincar hang below that upper track ( use the visible one on the lower track to its right in the distance as a guide ), and what would happen if the traincar traversed that track ? 
KEERASHHH !!! ... Aah !!!! ... Blub - Blub - Blub ...
Seriously, texture pictures are alot less complicated to create without mistakes, and far easier to correct if one is made. NOT fixing them is a sign of serious fuck-up-ed-ness in a game production.
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Impression which the Game Artists Put in Their Skybox backgrounds ( the 'Tall' aspect being a little too much repeated ) : 
Part of the New York City skyline/cityscape ( which various views of Rapture try to emulate ). Notice there are some VERY tall thin buildings ( due to the VERY high price of real estate in NYC ). But also notice many the shorter buildings (with different shapes) AND a vast majority being VERY short ( like only 6 stories ). The city skyline past 1936 did not change that much as WW2 greatly slowed new building in America ( as did the Roosevelt Depression, which was still going on ).
Skyboxes use STATIC picture surfaces, so having alot of realistic variation is EASY to paint into the textures (and thus the game). Having the repetition we saw ( another and another and another tall very pointy skyscraper ) really had no excuse.
BTW - That's the Hindenburg about a year before its disaster.
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