No, it's not "you attract what you are."
The subconscious mind seeks balance. I'm aware most people are telling you that you attract what you are. Let's use an example. You observe your target's past lovers, and notice she attracts the "bad boy". However, you look back and notice her father was kind, you were close enough to her to know about her sexual history--which was healthy. So, why is it that she attracted all these bad boys, who treat her like shit--despite the fact that she grew up in an environment where the male figure was kind, and treated her nicely.
The answer? Balance.
You may have even noticed this with yourself, and have a hard time understanding what it is. Not only does our subconscious mind seek balance, it has different needs such as security, and INsecurity--such as adventure, and new things. However, let's not dismiss the other reason for opposites attracting; they have an unmet need.
How do you take advantage of this knowledge?
You don't act like the complete opposite. Otherwise, this might scare them. Rather, you should embody the essence of the balance they seek. Perhaps your victim grew up in a very stable environment, so s/he may associate the bad boy image with adventure. If you don't care to be the bat boy type, show her you can provide adventure by posting pictures of you doing adventurous things. You still have to be similar/familiar enough where s/he feels a rapport with you.