Many people seem to think it's in reference to her being nicknamed "Snake" after her little feud with Kim Kardashian and Kanye West. Kanye put a crude lyric about Taylor in one of his songs. Taylor acted so offended and shocked. Yet, we come to find out she actually approved the questionable lyric over the phone. Kim posted a recording of the call on Twitter to expose her. She did have a bit of a backlash over that and many people began to catch on to how manipulative she could be.
But of course, it could also be something a lot more sinister. We know how significant the snake is in the Book of Genesis, and also all the theories about reptilians. Nevertheless, it does seem she is going to release new music very soon so her strange behavior on social media is no doubt to promote it. I wonder what kind of symbolism it will all have.