You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
My brain so wants to see this as a pair of equilateral triangles overlapping, but they aren't even isoceles. It can make one or the other seem symmetrical, but the other one gets the far circle warped back in space, or shrinks its diameter. Is that the intention? Same if rotated.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.