The title of the Cooper Hewitt’s recently opened exhibition isn’t a question—indeed, “How Posters Work” is very obviously a statement. And yet, when you consider the phrase from a slightly different perspective, you arrive at an intriguing question that’s at the heart of the museum’s exhibition: How do posters work?

It’s not something we often think about. We slap posters onto our walls or admire them from afar as we stroll down the street. We know we like how they look, we’re just not sure why we like it. Cooper Hewitt’s exhibition is an attempt to figure out the why, and in the process, come to a conclusion on how two-dimensional graphic design works in general.

One thing is clear: there’s no single path to a designing a poster with impact. Like most forms of graphic design, a compelling poster is a carefully considered sum of lots of tiny parts. In some ways, it’s like a big empty pot in a well-stocked kitchen: a totally blank canvas into which you can throw a number of ingredients. It’s how you assemble the ingredients that determines the success of your outcome.

In “How Posters Work,” we see this idea manifest itself in a wild variety of forms. The curators distilled its permanent collection of more than 4,000 posters down to 125 that exhibit fascinating insight into how graphic designers approach poster design and, more generally, their craft.

The show’s posters are organized into 14 categories, all of which explore a specific visual principle that makes the image work. Many designers lean on a single visual trick to grab your eye and effectively communicate their message. For example, in 1999, Michael Beirut was commissioned to design a poster for the Architectural League of New York’s annual Beaux Arts Ball. While mulling over the theme, “Light Years,” he realized that both words contained five letters, leading him to design a minimal, overlapping wordmark that shows just how powerful typography can be all on its own. Contrast that to something like Victor Moscoso’s  “Junior Wells” poster from 1966, an array of colors, illustration, and typography that melts down the page like an ice cream cone in summer. It’s a true sign of the ’60s, psychedelic and overwhelming.

The show explores visual tricks like establishing eye contact. A great example is Richard Avedon’s famed poster of John Lennon, a piece that was effective not just because of its bold, colorful graphics, though that would be easy to assume. You might not realize it consciously, but his gaze—fixed directly on yours—creates a profound emotional pull that attracts you to the poster. Contrast this to Waldemar Swierzy’s 1973 poster for Midnight Cowboy, an equally compelling poster entirely devoid of eyes. Swierzy’s work is a testament to simplicity with the character’s ruby red lips popping from an otherwise featureless face. It’s fun to compare that to Ladislav Sutnar’s work, which employes simplicity in a totally different way, using cut-and-paste geometric shapes to create a modern, eye-catching poster for Addo-x.

Lessons abound in “How Posters Work;” in fact, the show feels more like a graphic design crash course than traditional museum exhibition—not that the two are mutually exclusive. But the lessons to be gleaned aren’t just about posters. Perhaps Ellen Lupton, one of the show’s curators, says it best in the exhibition’s accompanying catalog: “This is not a book about posters,” she writes. “It is a book about how designers see.”