While viewing images of summer in the View-Master, one of the images that Olaf sees is of Motunui, the island from Moana.
When Olaf first wakes up after getting knocked down the hill by Elsa's cape, the lines he says about being alive and being able to juggle are a reference to Burl Ives' Frosty the Snowman (1951). Frosty can juggle, but Olaf cannot.
Frozen (2013) was the last movie WDFA made with Renderman software, after which they switched to the more advanced Hyperion. To recreate the scene of Elsa conjuring up Olaf, and continue it from his perspective, they had to retrofit a computer with Renderman, and dedicate a few servers on their farm to work with it.
During the scene where Oaken shows Olaf pictures of summer, most (if not all) of the slides shown are recycled animations not only from the original Frozen (2013) movie, but also from Tangled (2010), Zootopia (2016), Moana (2016), and Frozen II (2020).
This short film takes place during the events of Frozen. It starts with Elsa creating Olaf while singing Let It Go, and ends with Olaf walking towards Anna, Kristoff, and Sven, like in the 1st Frozen movie.