Whenever Zuko visits his Uncle in prison, Iroh is seen sitting in the light and viewed through the bars, not behind them - whereas Zuko is always in darkness with the 'camera angles' viewing him behind the bars. This symbolises Zuko's current inner turmoil and the fact that he feels trapped by his father's expectations and being loyal to his nation while still trying to figure out what is right.
During this episode, Katara ask if there are bathrooms in the Spirit World. Sokka then tells her "as a matter of fact, there are not." This is a reference to an earlier episode when Sokka is trapped in the Spirit World for 24 hours and upon being freed he immediately needs to use the bathroom.
This marks the introduction of Greg Baldwin voicing Uncle Iroh. Although Uncle Iroh has been seen in Season 3, this is the first time he has spoken since the passing of Mako, Iroh's original voice.
Sozin is shown riding a blue dragon and Roku a red dragon; the motif of red and blue dragons is used similarly to the concept of yin and yang in the Avatar world, with them frequently shown circling each other in a manner similar to Tui and La (the fish-shaped spirits more directly stated to represent the concept).
The gift headpiece that Sozin gives Roku is a guan, a type of ornate covering that goes over a topknot. The show shows how the guan is held in place by a pin called a zuan. In ancient China, arisocratic young men had a coming of age ceremony where they pulled their hair into a topknot for the first at age 20.