An illustration of how strictly HK self-isolation for incoming travelers is from HK Vogue contributing editor Declan Chan's insta (HT @tara_mulholland)pic.twitter.com/LQzWujthGB
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
The geofencing doesn't seem that hard at all, the precision of a phone's GPS is what seems impressive. The corners of a 1500 sq foot studio aren't that far apart.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.