After Dottie (wearing Peggy's brand) kisses Peggy, Peggy pulls back Dottie's sleeve to reveal handcuff scarring. The sleeve that Peggy pulls back is Dottie's right sleeve. During the "previously on" at the beginning of the episode, Dottie is shown to handcuff her left wrist to the bedpost, not her right.
When talking about Angie, the caretaker called her an actor. In the 1940's, females were known as actresses.
When Dottie starts to set up her shot, she puts her eye right on the scope. No trained sniper would ever do that mainly because the recoil would damage the eye. However, she is not taking a shot but using the scope to see the detail of the message Dr. Ivchenko is sending to her.
Black Widow kisses Peg while wearing the "mickeyed" lipstick. Since she was wearing lipstick when kissed by Black Widow, she should not have been affected by it.
When Peggy and Jarvis meet at the automat, the song "It's a Good Day" is playing in the background. However, the show is set in 1946 and the song wasn't written until 1947.
Peggy and Jarvis walk past a 1948 Chevy sedan. This episode takes place in 1946.
When the SSR Agents are questioning Angie, she begins to cry. If you look to the left side of the screen, you can see Daniel Sousa's actor breaking character. He smiles and hold back laughter.