Observant commuters have noticed that there's something different about Coca-Cola's headquarters tower this week.

Three sides (west, east and south) of the 26-story building on North Avenue are draped in huge white sheets of fabric. Workers seemed to be preparing to put up a fourth sheet on the north side of the building, and a stage was set up in the courtyard. Creative Loafing reported that test images were projected this week on the sheets, which first appeared Saturday.

Twitter was abuzz Thursday with chatter about Coke's swaddling. "Wonder what their plans are?!" said one commenter. "Can't wait to see the projection!" said another, both from Atlanta.

Several industrial-size projector machines were set up in the entrance area of the complex Thursday afternoon. Across North Avenue, another cluster of machines was perched on the roof of a Georgia Tech building. Another batch of projectors was reportedly in the parking lot of a nearby hotel.

The company is celebrating the 125th anniversary of the Coca-Cola brand with a gathering of international media, presentations by executives and, on Saturday, a concert for employees. (Also, there will be a "dance mob" of 150 people Saturday, for good measure.) The white sheets are part of the celebrations, which includes a private event at the headquarters building Friday night.

But Coca-Cola is not giving out all of the details about its plans. Its public relations representatives remained coy Thursday.

"What sheet?" said spokesman Petro Kacur. He declined further comment.