Lana's injury keeps flipping from shoulder to shoulder. Elevator: left. First gurney: right. Second gurney: left. Hospital: right. Following episode: left.
When the elevator opens, it appears that Lana was shot on the left side, but when the medics have her on the gurney, they are applying pressure with a bloody bandage on her right side. Then when you see Lionel talking to her still at "he Planet" newspaper office, while she is on the gurney and they zoom in, the "wound" is back on the left side again.
Chloe shows the newspaper to Jimmy with his photograph on it. The photograph is not the same when a close-up is shown. The first two pictures are a headshot of Jimmy and a distance shot of the police, but when a close-up of the paper is shown, the photos are now of Jimmy shaking hands with an official and of the gunman in police custody.
With the mirroring already mentioned regarding the injury, the decoration on Jimmy Olsen's shirt swaps from left to right.
The episode is set in 1940 however, when Lois and Lex kiss there is a 1949 Ford pickup in the background.