When Almanzo runs into Brenda Sue for the very first time, he gives her a perfectly normal "Hello, how are you doing?" and then goes on to say that he hasn't seen her in months. It was clear that Brenda Sue was an unexpected out-of-town visitor in this episode. If an old friend walked up to you out of the blue after all that time, wouldn't you be surprised to see them? The way Almanzo greeted her, you would have thought that he saw her every day of his life.
When Laura says to Brenda Sue, "No, you witch! I found out!" and pushes her down, you can see that Melissa Gilbert (Laura) is on the brink of laughter, but they cut the camera away from her face just in time.
Notice the black, jaggedy imprints of dirt that are caked on Laura's face when Caroline pulls her away from Brenda Sue after their fist fight. Those marks are much lighter and positioned differently in the next scene, when Laura and Caroline are talking in the restaurant kitchen.
Almanzo: (in the bathtub) Beth!
Laura: Did you call me?
Almanzo: Yeah, darling, there's no more towels!
Laura: I didn't get to them today.
Almanzo: Well, that's fine, I'll just sit here and watch my skin wrinkle up!
Laura: I'll get them done tomorrow.
Almanzo: Well, how am I supposed to dry off?
Laura: Almanzo, I'm sorry. Use a sheet!
Almanzo: That's great. Then maybe tonight, I can go to sleep on a nice clean towel!
Charles: I just saw Almanzo on the way back from Sleepy Eye. He was all excited about coming home to see you. He even had a present for you.
Caroline: Charles, I don't see how that has anything to do with any of this.
Charles: Well, it's just that he doesn't seem to paint the picture of a guilty husband.
Laura: Well, it seems that Almanzo's getting very good at that.
Charles: There's one other thing. He told me that you were crazy to be jealous of Brenda Sue. He said the two of them shared one thing—an interest in music—and that was all it was, because he could never get to liking her.
Laura: Well, I can certainly see whose side you're on!
Charles: I'm on the side of making sure this is not all a big misunderstanding before doing Almanzo Wilder great bodily harm!
Harriet: I just got a beautiful new nightgown from Paris. Remember how you admired it in the catalog?
Nels: That's nice.
Harriet: Want me to put it on?
Nels: Not really.
Harriet: (silence) I got a nice pretty one from Minneapolis. You liked it. Nels?
Nels: Yes, dear?
Harriet: Oh, Nels, I'm only trying to make you happy. Isn't there something I can put on?
Harriet Oooh, what?
Nels: Put on a paper bag!
Store Owner: My late husband never got me a gift unless we had an argument, so finally, I decided I would argue with him all the time. That way, I'd get something every day.
Almanzo: You must miss him.
Store Owner: Why should I miss him? I see him at home every night.
Almanzo: I thought you said your late husband.
Store Owner: I did. He's always late. That's what we argue about.
Almanzo: Laura, I'm gonna tell you something. You want to know what your being jealous of Brenda Sue is? Stupid, that's what. Just plain stupid!
Laura: Oh, really?
Laura: Well, maybe I'm too stupid to cook supper! (shoves ball of dough in his hands and storms out)
Laura: Almanzo, I'm doing the best I can. Why can't you understand that?
Almanzo: All I understand is that I work all day, and I come home to a half-cooked meal and a house that I can't sing in, because you've turned into a library!
Laura: Where are you going?
Almanzo: Outside to play for the cows!