This has to be the most amusing turd to ever fall from a woman's mouth.
It is an invitation to be dull, bland, and boring - so that she can quickly figure you out and decide not to fuck you. That let's her save her sexuality for the more distant, intriguing, maddening guys. The ones she does fuck, because they intrigue her with their ways.
Note: not one indication that you should improve yourself. Oh no! She wants you to "just get it" yourself, rather than have to be told.
This is what pisses women off so much about the Manosphere. All these men being told what her cryptic (oracular?) utterances really mean. It's hard to appear to have feminine mystique when what she says is being translated into realspeak that men understand.
"Just be yourself."
The thing is that for a woman, it is relatively easy to get sex.
Men generally have to jump through hoops of her designing ("you missed that one - no sex for you!") to get a shot at a fuck. She'll often have several men on the go. It's just easy for her, because female seduction amounts to: show up naked with beer. So you can see, this bullshit utterance is not grounded in the slightest in male reality.
Note: it's because it's grounded in female reality. All women communicate on multiple levels, they constantly evaluate and re-evaluate what other women say.
This is why she can get into a snippy depression so easily. An on-the-surface-innocuous-remark can carry an under-the-surface sting. Or if she doesn't "get" the underlying message, she'll obsessively go over and over it until she gets it. If ever.
"Just be yourself."
Any woman who says this is (ironically) likely to be boring as fuck.
Which is highly amusing for the more-aware man who knows the underlying message. It's an immediate DLV for the woman: that she drops out with some low-end bullshit platitude instead of something a little more useful in life. It shows that her low-end lackadaisical effort is her general approach to everything: lazy and ultimately sad.
Note: it is this laziness which is chief indicator of her low value. A discerning man will leave her to the PUAs for a pump'n'dump, looking for the better quality girls.
This is why men should never listen to dating advice from women. They are clueless, because they don't have the reality that a man does to give them true perspective and to allow them to give worthwhile advice. In any area of life at all.
Seriously, she should just go back to the kitchen and let men deal with the outer world while she is feminine and supportive in their home. If nothing else, the tremendously reduced stress of not having to deal with the bullshit that men do will have two benefits for her:
1/ she'll be less bitchy (and therefore more worthwhile to be around)
2/ she'll frown less (which reduces wrinkle-lines and helps her remain youthful and beautiful longer)
What, you don't think that men had both of those things firmly in mind when they invented household appliances?