It can be hard to get a handle on Wal-Mart with its 2.1 million workers, 37.2 square miles worth of retail space and $447 billion in revenues.

As the retailer has settled into utter domination and fended off accusations that it unfairly overwhelms main street stores and doesn't treat workers properly, it's been tricky for the company to talk about itself. Wal-Mart has a story to sell to Wall Street, but also has to keep peace with employees and customers.

One small but telling piece of this effort is the cover of its annual report, the evolution of which illustrates the company's move from regional upstart bragging about its growth to global behemoth trying to connect with everybody and only partially succeeding. Wal-Mart was always a company on the move and this showed up regularly in its reports to shareholders, five of which prominently feature tractor trailers -- the company was always more practical than sexy. The first shipping-centric cover came in 1976, with one lonely truck pushing out onto the vast empty highway (actually, it's a two-lane road), inviting investors to just imagine the possibilities while at the same time continuing to project a small-town image.

By 1980, that truck had apparently found its destination and the company was ready to talk money, shouting about "Wal-Mart's billion dollar year" with bright blue lettering on a dull gray background.

Having hit the billion-dollar milestone, the covers drifted, as they have periodically. Several covers were nearly all white, there's an artsy shot of a truck in an empty parking lot at night, a cover celebrating the firm's 20th anniversary.

Then, in 1984, Wal-Mart latched onto the slogan "Our people make the difference" and there's a series of pretty garish covers featuring delightfully Midwestern employees smiling as they stock shelves; one executive works the phone from a spartan desk. In 1985, one of the employee's eyes are closed. The 1986 cover touts "The People of Wal-Mart," but there's no picture to go along with the tag line, just a black background.

The people of Wal-Mart get more cover shoots, but the tag line goes away. A more magazinelike layout takes over and, in 2000, declares Wal-Mart "Retailer of the Century" and boasts of international expansion. Wal-Mart was clearly ready to brag again. A worker named Karl, of course, holds a German flag. (The retailer struggled in Germany for years before pulling out.) Smiling workers of seemingly every demographic take over for a few years.

By 2006 the customer is firmly in the center and shopping carts abound. Wal-Mart, with its growth-curve flattening out, seemed ready to highlight the people who shop there.

The go-go year of 2007 features a shopping cart overloaded with goodies. Then the economy turns. The 2008 report, which came out just as the financial crisis started to brew, underscores, "We save people money so they can live better." The image is odd, almost a wake for the economy's bubble days. There are three framed photos  of shoppers passing through various life stages -- a birthday, a wedding, a graduation. The pictures are grouped around a pair of receipts.

The save money and live better theme continues today.

The recently released 2012 report marks the company's 50th anniversary and is probably its slickest production yet. The anniversary and the mission statement are right up top. There's a shot of an early Wal-Mart, a mix of employees happily plugging away. There are also shoppers, both in the store and enjoying the benefits of all those low prices at home. The company name is centered at the bottom. It's like Wal-Mart after 50 years has figured out, at least visually, how to get out of its own way.

The expert reading of the Wal-Mart covers is split, at least among the two experts I contacted.

"To me, it isn't too polished which communicates a certain amount of straightforwardness and authenticity," said Mike Toth, president and chief creative officer of branding firm Toth + Co. "They are keeping it real."

He thought they could do more with the save money, live better promise, though.

A chief marketing officer of a major retailer, who requested anonymity, said Wal-Mart was "all over the map" and that the family values theme seemed "token and inauthentic."

"The multi-culti casting is extremely contrived and forced as though the brand is attempting to speak to every possible demographic -- 'checking off' the boxes," the marketing executive said. "They've missed a major opportunity to create an ongoing and consistent identity that is authentic -- for the people and of the people -- which would engender lasting trust."