What does “No pressure” mean when you’re meeting someone new?

Question

Time magazine (6 Aug 2014) carries an article titled “Our Brains Immediately Judge People” and subtitled “We make calls on trustworthiness almost instantly” that says research at Dartmouth College and New York University revealed the human brain judges trustworthiness or untrustworthiness of other people in about 30 milliseconds. The article concludes:

“This, the researchers conclude, is evidence that our brains make judgments of people before we even process who they are or what they look like. Keep that in mind the next time you’re meeting someone new. No pressure.” http://time.com/3083667/brain-trustworthiness/

I’m not clear about what “No pressure” here exactly means.

Does it mean no need of feeling pressure in trying to read and judge trustworthiness of a person you meet for the first time?

Could you tell me “no pressure” from what? Can I rephrase it with a simple “No sweat”?

Answer 1

In this case

No pressure, used in this way, is meant sarcastically to indicate that something is, in fact, important and may put pressure on you.

You could rephrase it as "no sweat" if you implied sarcasm in "no sweat".

In this case, it is just a mildly humorous sarcastic comment—they're saying that since people make judgments of you before they even process who you are or what you look like, you may feel social pressure the next time you meet someone new.

Another example of no pressure in this sense is:

If you cut the wrong wire when disarming the bomb, it will explode. No pressure.

You could, of course, rephrase it like this, and many other ways. The last bit is sarcasm.

If you cut the wrong wire when disarming the bomb, it will explode. No sweat, though.

Alternatively

You can still use it non-sarcastically—it's dependent on context. For example, if someone's going through a rough, sensitive time and you want to offer them help but not make them feel obligated, you could say:

Let me know whenever you want to talk; no pressure.

Answer 2

"No Pressure" is universally meant ironically, since you should feel pressure. Here, the pressure is that your brain is silently forming your entire response to a person before you are aware of it.