Trivia: Just after Linus seals his letter to the Great Pumpkin in an envelope, he walks past Lucy who is sitting on the floor watching TV. In her hands, Lucy is holding an issue of TV Guide Magazine. On the cover? Lucy, sitting on the floor in the same position, wearing the same blue dress. (00:07:00)
Trivia: Kathy Steinberg, the actress who voiced Sally, almost had to be replaced. Just as they were approaching the end of her recording sessions, Steinberg's mother rang executive producer Lee Mendelson one night in a panic because Kathy had a loose tooth and the gap in her teeth could cause a lisp in her voice that would sound different from the dialogue they had already recorded. The crew had to rush Steinberg into the recording studio as soon as it opened in order to get the rest of her lines on tape. Mendelson said that Steinberg's tooth dropped out as she spoke her last line.
Answer: From what I've seen, usually Sally is often annoying Linus with her flirting when he has nothing in common with her, or he's just trying to do something to help her and she tries to make it into more. Here, Sally's comments make Linus think she believes in the Great Pumpkin too, or is at least interested in hearing more about it. It's more that he's excited she likes the same thing as he does. Later in the pumpkin patch, he's happy she's there because he wants to share the experience with someone, not because he has any feeling towards Sally.
Bishop73