Blinking red tie = Morse code? https://images.axios.com/RdQeFj3w_RWfAmlZeaEZZpjtm68=/0x0:1920x1080/1920x1080/2018/10/02/1538508825340.gif

From HRC’s twat:

https://mobile.twitter.com/HillaryClinton/status/1047551495980429312