Raw source: #539003

Too lazy to translate the reference explanations at the end, so here are just some essential points:

1) The song she’s singing at the beginning is one of the Sazae-san theme songs.

2) Read about Glico caramel and toys here.

3) Hato no Oyomesan is a comedy manga series (which also got a flash anime adaptation by DLE).

4) PGP = Panda! Go, Panda! (a classic animated film).