In airing order, the previous episode was Blue's News, meaning the audience may not know who Paprika is; however, it should be noted that it made no sense for this episode to air after Blue's News because Paprika was not featured in this episode while she was introduced in Blue's News.
Steve's arms go through some scenery in Boo's home.
When Steve sees the 2nd clue on a shadow, the shadow of the tree branch doesn't appear to be connected to anything.
When Mr. Salt asks Steve about the second picture, a blue line can be seen on the top of the screen.
When Shovel, Pail, and Steve see a shadow of a tree with a bird's nest, there is a black stripe on the left side of the background. Steve appears to be standing in front of the strip. Also, before Steve and Blue see Mr. Owl, there is another black stripe on the right side of the background. Blue's ears appear to be staying in front of it. Steve even goes behind it when he heads to the bedroom.
In the opening of the episode, when Blue jumps out from behind the house, Blue suddenly moves to jump out from behind the bush animation a split second before she lands on the sidewalk.
When Mrs. Pepper shouts "It's fantasAHHH!", Blue's ears raise before Mrs. Pepper yells.
After Steve says, "Just kidding. It's me, Steve", Blue's mouth moves, but her bark sound comes about a second late.
At the end of the episode when Steve and Blue go meet Mr. Owl in the bedroom, Boo appears out of nowhere before floating in the bedroom to meet Mr. Owl.
When Mrs. Pepper shows the viewer the first picture, Steve disappears from behind the picture, but when Mrs. Pepper jumps back, he reappears. Steve should have been seen through the gap.
When Steve asks Blue what she's doing under the blanket, taking a much closer look shows Steve's hand is actually going through the blanket.