Well according to the glossary...
"
If a advertisers Age is verified, we can confirm we have seen an official document from the advertiser confirming their date of birth."
...it seems in order to be verified, you have to show EI some sort of official documentation with your age/date of birth on it.
I won't reveal the girl who I made reference to earlier as that wouldnt be fair but I know what I saw, verified as 30 and then verified as 27. So how did this girl get verified at two different ages? Two different passports?
You can see a verified profile by clicking on the ad profile of Cherry, who started the thread, Im sure she wont mind being used as an example. If you hit the verfied icon beside her age, you get the glossary Alex.