The print version of that article by Billy Kenber, "Guantanamo Bay prison camp still at work on its image," apparently described Navy Capt. Robert Durand, who heads the public affairs unit at the base, as "thickset." The online version now reads: "Durand, a tall, muscular man with glasses, talks about his work in big, broad terms." Furthermore, the print "correction" is called a "clarification" online, and reads differently: "An earlier version of this article incorrectly described Navy Capt. Robert Durand’s physical build. He should have been described as muscular. This version has been corrected."
Post education reporter Emma Brown thinks this is the paper's "Best ... correction ever"; I think it might require a correction of its own. After all, here is what Durand actually looked like in this April photo by the Associated Press.
Let's assume that, after this photo was taken, Durand didn't begin bench-pressing 400 pounds and pounding protein supplements. He's clearly not "thickset," meaning "having a short, thick body." But he also doesn't seem particularly "muscular," meaning "having large and strong muscles." He seems more "fit," as Slate's Josh Voorhees observes, or perhaps even slender. We can't know for sure, of course, until we see Durand with his shirt off—and Kenber gives no indication in his story that he was afforded such a view.