Near the end, Uncle Iroh is seen playing a tsungi horn, and next to him is a small statue encrusted with red gemstones. Both of these items came to be in his possession from dealings with merchants and the pirates as seen in The Waterbending Scroll (2005).
The Blue Spirit mask was originally supposed to be red because it is a Fire Nation mask. However, animators felt the mask looked too much like "a Korean Spider-Man," so the mask was changed to blue instead.
At the 6 minute 12 second mark of the episode, a horn is blown by a fire nation troop to alert others of the Avatar's presence. The sound the horn emits is the same sound that opens the theme song for the reality competition show, "Survivor."
Aang's wanted poster says "Wanted: The Avatar. This fugitive has the ability to airbend, being able to create tornadoes and run faster than the wind. Be careful beyond careful when capturing. Issued under command of the Fire Lord."
Avatar Extras says that the Yu Yan's fortress used to be an Earth Kingdom trading outpost before the Fire Nation conquered it.