Typically:

Comfort test - You showed too many alpha traits in comparison to her expectation and your girls is insecure whether your SMV is too high.

Shit test - She either doesn't know your value or you showed to many beta traits. She is not sure you are worth her time.

On another note: Girls often classify you as BB or AF and compare your appearance to the expected alpha and beta traits of the corresponding class.

So if your girls is giving you a lot of comfort tests (especially in the beginning of the relationship) you are probably classified as BB and thus your beta qualities (comfort, long-term security, stability, ...) are tested. If your girl is shit testing you a lot in the beginning of the relationship you are probably classified as AF and she tests your alpha traits (attraction, short-term security, activity, ...).

One has to keep in mind that due to the biological imperative girls seek more often BB's than AF's. Only during her ovulation time (3-5 days) a girls desires physically to bond with an AF. Then she is also active and eager to bond. The other time of a month she is more likely to look for BB's but does not really pursue it.