That shot reminds me of an atom... which is cool as this station would be a fundamental part of the Federation's presence in that area of space.
On a side note: what I loved about Yorktown was its scale. Trek has always tended to keep things - for lack of a better term - TV sized, the kind of stuff you can do on a television budget. Even the films would embellish things, but with the exception of V'Ger and perhaps the Scimitar, there hasn't been anything that has been jaw-droppingly gorgeous and monumental in scale.
Finally, somebody said - "hey, we have a blockbuster budget - lets build a blockbuster thingy"