Disks appears to rotate.pic.twitter.com/LovDvhnzFh
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
thx - a little more - I wonder if one puts something in the center that forces focus it would then make the effect even more pronounced without effort
It is suggested that some eye movement feeds this illusion. It will make the effect weaker to put a fixation point.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.