what does the phrase "I HAVE ATTITUDE" mean in this picture?
To have attitude is a relatively modern idiom, originating in the US. The OED still only includes it as a draft addition to the dictionary, from 1997. Though the examples go back to 1962.
It is in two parts -senses 6a, and 6b.
a. Aggressive or uncooperative behaviour; a resentful or antagonistic manner. In phrs. to cop an attitude, to give attitude, etc., to assume such a manner. slang (orig. U.S.).
b. Hence, any highly independent or individual outlook, approach, appearance, etc.; self-possession; style, swagger, front; esp. in with (an) attitude. slang (orig. U.S.).
Though the OEd does not include it, it is sometimes expressed as an attitude problem.
As the comments on the question say, 'have attitude' is being tough/strong-willed/assertive/kick-ass.
The usage here emphasises this meaning even further though: 'I have P.M.A.' appears to be playing on 'I have PMS', i.e. premenstrual syndrome. Premenstrual syndrome is often associated with being grouchy and irritable, and with 'PMA', this slogan is slamming that stereotype with the result of coming out even more tough-skinned and strong than by just saying 'I have attitude'.