For example: she'll stop giving you any positive attention for a while.
She doesn't walk away or turn her back on you or anything - She is just going really quiet and looking to see if it affects you.
This will happen every single time. The interaction will be going really well... and then all of a sudden it goes flat for a minute or two.
She is looking to see: "does this guy freak out or does he REALLY believe I actually like him?"
She is looking to see "how does this guy react? Does he know that I like him, or is he insecure and thinking he has done something wrong?" It's important to demonstrate that certainty, that unwavering belief, that ability to not be shaken by anything because you believe in yourself.