I'm a bit concerned by the original wording of your question (which I've edited) that you are under the impression that eNotes will provide a ready-made assignment for you to turn in. This of course is--using the literary and rhetorical device of "idiom"--way off the mark (meaning very very mistaken).
Since time is limited, I'll point out the first three I make note of.
Literary devices are said to be used in literature and, while I quite admire Malcolm Gladwell, I don't believe his article reaches literary standards (this is a comment using the device of ironic satire). When language schemes and figures of speech are used in prose writing of the periodical sort, e.g., The New Yorker (though there are those who claim literary status for The New Yorker, a comment using the device of satirical irony), they are called "rhetorical devices."
One of three rhetorical devices that Gladwell uses is the appeal to the expert witness, also called ethos, and he employs this device when he references someone else's research and when he uses quotations, even when he quotes his own writing.
Expert witness, ethos: quotations, even quoting himself: e.g., "There are no instant experts in chess—certainly no instant masters or grandmasters."
Another is hyperbole, which is what we commonly call exaggeration but exaggeration that is for a rhetorical (or literary) effect and that is deliberately thought out and precisely planned and employed. Hyperbole is saying that a thing is far greater or lesser in some way or another than it actually is, e.g, the following means "he" was extraordinarily talented, even supremely talented (hyperbole here also combines with idiom, which is a cultural expression of understood meaning):
Hyperbole: "He has talent by the truckload"
Another rhetorical device used is that of satire, whose presence we have already met in my own wit. Satire is meant to point out an error in thinking or behaving or believing by using mildly sarcastic or ironic humor to call attention to the wrongness or foolishness of the error.
Satire: "like jumping really high, running as fast as you can in a straight line, or directing a sharp object at a large, round piece of cork..."