Emma uses the alias Princess Leia, this is an obvious Star Wars reference. At the time Disney had just completed its purchase of Lucasarts (including the rights to the Star Wars franchise) meaning that this reference is in fact a Disney reference.
Captain Hook uses the false name Prince Charles, in the original Peter Pan writer J. M. Barrie referred to Hook's look as similar to that of Charles the 2nd.
Ginnifer Goodwin's real life pregnancy was written into the series for the later half of season 3. However, while Snow White/Mary Margaret had already given birth to her baby by this point of the story, Ginnifer had not and was still very pregnant during the filming of this episode. Any scenes of Snow White from the past were created using a body double, clever camera angles, and recycled footage from previous episodes.
When Hook and Emma first see Regina in the Enchanted Forest, she is styled like a female version of the cartoon Captain Hook from the original Disney film. Hook and Emma made fun of the cartoon version's look earlier in the season.
Snow is shown felling a tree with a righthanded broadaxe. These tools could, with sufficient time and effort, take down a tree. But they are designed to shape a chopped down round tree into a squared off, straight sided hunk of lumber. Oddly, a felling axe has a smaller head and longer handle.