Normally when members of the zodiac are hugged by someone of the opposite sex, they transform instantaneously. But when Hatori catches Tohru, it takes a moment for him to transform.
Answer: Two words- Slow Motion
When Momiji hands Tohru her drink, the can is yellow, but when the screen gets a close-up of Tohru, the can is pink! So was she drinking from a pink can or a yellow can?
Shigure: Oh, Tohru, have you asked Hari what Zodiac animal he is?
Hatori: One more word, Shigure, and the entire publishing industry will know every embarrassing thing you've done since you were four.
Shigure: Understood. My lips are sealed.
Hatori: So what brings you here?
Shigure: I suddenly had this feeling Tohru was here in need of a rescue. Call it a "writer's intuition" if you will.
Hatori: Well, that's a lie. You only came to see the New Year's preparations, didn't you?
(Hatori wakes up with nothing but the coat that Tohru put on him.)
Hatori: Did you see it?
Tohru: No, you see...I...
Hatori: I mean my zodiac form.
(Flashback with Hatori and Kana.)
Kana: Say, here's a question for you. When the snow melts, what does it become?
Hatori: The answer is water, of course.
Kana: Bzzz-Bzzz!! Nope! It becomes spring! I think spring is my favorite time of year.
(Flash forward to current time later in the episode. Hatori and Tohru are talking.)
Hatori: Tell me, when the snow melts, what does it become?
Tohru: Huh? Mmm, let's see. It becomes spring, right? So, even when it's cold like this, I always remember that spring is on its way! It's sort of neat to think about. No matter how much snow there is, it's all going to melt. It always does. I think spring is my favorite time of year.
(Tohru is inside the main Sohma house.)
Hatori: Please, make yourself comfortable.
Tohru: (thinking) I think that's easier said than done!
According to the manga, Hatori's sign is the Dragon, but the form he assumes in this episode is not what the viewer expects.
It is revealed who hurt Hatori's eye, and that Hatori can barely see out of it.
Momiji informs Tohru about Hatori's former love, Kana.