You may recognize the towering figure on the front of the card that comes with Guph's new mirror. It's the Lookout, last seen vacating his post in Chapter 2 of Lost In Oz, entitled "Dorothy Meets the Lion."
Posing as Guph's reflection, Reigh reminds Guph that he's made quite a few enemies in his ascent to the throne, including the Growleywogs. You may remember Chapter 10 of Lost In Oz, entitled "Bogspeed Little Shanks!," when Guph turned his back on the Growleywogs, causing them to unite with Dorothy and her friends.
Guph declines to tell his reflection where he's going to hide the belt, warning, "You never know who might be listening in." Reigh reacts that Guph does have a point, probably because Reigh himself gave this warning to Toto when they first met in Chapter 2 of Lost In Oz, entitled "Dorothy Meets The Lion."
Toto's run through Emerald City finds many of the friends Dorothy has made in her journey through Oz, including: the Traffic Flower from Chapter 7, "Little Black Lies;" Toofah, the Nometensian child from Chapter 17, "Villa Roquat;" and Tred the Wheeler from Chapter 18, "The Magic Map."