Continuity mistake: In Lesson Zero, when Twilight is going to collect the cupcakes, there are 12, then there are 10, and in the next shot the icing is all mismatched when it should be all pink.
The Return of Harmony, Part 2 - S2-E2
Continuity mistake: When the Mane 6 are running away from the changelings, before the fight scene, Applejack's hat disappears, reappears in the next shot, and then does the same again.
A Canterlot Wedding - Part 1 - S2-E25
Continuity mistake: When the main six are running away from the changelings, Applejack's hat isn't there. In the next shot, it's back. That happens for the next two shots.
A Canterlot Wedding - Part 2 - S2-E26
Continuity mistake: In the shot just before it goes back to Twilight and Cadence when they are about to escape, it shows Lyra Heartstrings in the crowd. When the shot does go back to Twilight and Cadence, it shows Lyra as a bridesmaid. Likewise, in part 1, Lyra is still a bridesmaid.
Answer: The smoke floats a few feet away from Twilight and close to the camera so you might think that the smoke is right in her face.
Lily Harrison