Sometimes it could be an illusion and sometimes it could just be a reality shift. Our brains are bombarded with gazillions of bits of information. I frequently get a glance at something only to glance back and it looks like something else completely. I kind of view it as a glitch in the Matrix. I know that sounds weird, but I’m weird anyway.

Also just to mention,the way our brains operate is so complicated and unpredictable that “eye witness” testimony is getting a bad rap in the legal system. They have done studies where they have room full of 50 people or so. Then they have a person run in grab someone’s backpack and run out. Everyone sees something different! They can’t even agree on gender or skin color.