On the long list of weird things I'm peculiarly interested in is the 49-star American flag, which was the official flag of the United States for just one year and accurately represented the number of states in the Union for 48 days. (Alaska was admitted to the Union on January 3, 1959; the new flag was officially adopted on July 4; Hawaii was admitted on August 21; the 50-star flag was officially adopted on July 4, 1960.) A side effect of this interest of mine is that I'm keenly attuned to the union (i.e., the blue field of white stars) and can notice pretty instantaneously when it has the wrong number of stars.
Which is a really roundabout way of pointing out that the American flag seen in the background of this illustration of the new Justice League of America by David Finch is drawn incorrectly. Note that the stars in the bottom row are immediately below those in the row above, which is not how they're arranged on a 49- or 50-star flag. That sort of grid pattern was most recently seen on the 48-star flag, though it doesn't seem to be one of those either. Hard to say, though, what with how the flag is furled.
In fairness to David Finch, he's Canadian. On the other hand, he's also not that good an artist, in my opinion. He's fine when it comes to pin-ups like this one, but his visual storytelling skills are crap, and he's always seemed to lose interest once the sexy bods are drawn. (or example, if you click on the photo to see it at its full size, you'll note that Green Arrow's bow appears to have pulleys like a compound bow, but a single string like a traditional one. And that arrow seems way too big.)