If they printed more than a certain number, then they need an EL - that number depends on which stock site it was licensed from. Using it in print is permitted under a general license, but if they printed more than say 500,000, depending on the stock site, then they need an EL. Hope that clarifies it for you.
I hope you picked up a brochure. When you see such a massive use, it makes you feel like even the EL isn't really payment enough.
