The artist who paints Eloise and Leon's picture in the movie is Hilary Knight, the same artist who illustrated the books the movie is based on.
The line, "think pink", and indeed, the whole pink theme comes from Eloise creator Kay Thompson's iconic role in Funny Face, also starring Audrey Hepburn and Fred Astair. Kay Thompson sings a song with the refrain, "think pink" in that film.
The episode won an Emmy Award for Outstanding Music Composition for a Miniseries, Movie or a Special (Dramatic Underscore).