Bakemonogatari is a show about damaged people. Bad people. Socially awkward people. Fetishistic people. And somehow it manages to pull off a conversation with all these traits and still make it sound both convincing and proper. In response to Nick's W&L on episode two, I had asserted that the first half of the show was a depiction of Senjougahara's willingness to expose herself to him and for him. There was a degree of trust that she placed in him, and indeed, felt that she owed him for her new lease on life as it were. This episode's fantastic back and forth dialogue adds to this dynamic.
First things first, let's set this fact in stone: Senjougahara is a marvelous tsundere character type. In anime tropes, a tsundere's inner feelings are soft and mushy (deredere) while their outer shell is harsh (tsuntsun). This is particularly true when said tsundere is involved with a character she is attracted to. However, what Senjougahara does to excel even further at this trope and bring her character beyond a mere archetypal tsundere is the balance of power she sets for her relationship with Araragi.
The truth of the matter is, despite their overt displays, a typical tsundere is ultimately the subservient half of the relationship. (Much like how yanderes, despite their outer display of soft cutness, are the dominant side in a relationship in violent ways.) what differs about Senjougahara is the fact that her words and acts towards Araragi are authentic. Lets take a look at this first exchange of words between the two.
S: If possible, I wanted you to see it [these clothes] first.
A: That you wanted to show it to me first... How do I put it...? It's beyond lucky, I feel honored.
S: I didn’t want to show them to you, Araragi-kun. I wanted you to see them. The nuance between them is completely different.
This line of dialogue is significant because of what is not. Read the following and see if it sounds familiar.
"It's...it's not like I wanted to show my clothes to you."
There is no masked embarrassment in Senjogahara's words. No bashfulness. We know what response she wanted to illicit from Araragi. This entire exhange is flirtatious by design, both for the sake of Araragi and for us the viewer in both a verbal and a visual sense and appeals to the fetishistic nature of both him and us in a subtle but purposeful moment of fourth wall breaking. Her actions are designed to please, but not place her in a subservient position. She has her own will in the matter, and lets him see just what she is willing to offer.
The next portion of the conversation drifts to her need to do something for him. She says she wants to be "friends on equal footing". That line is not a joke on her part, some bashful attempt at a confession. The long banter following that line, her list of oh so many potential sexual favors she would do for Araragi (all yet more fan service for both our sake and his) is a display of both trust and confidence she has in him that he would not take her up on anything so shallow. She wants to do something special for him on a more personal level, and she both trusts, and knows in an almost overbearing manner, that he would only have her do such a thing, even when all other options are open.
To phrase it in another way, she is not offering to be friends on an even footing with him by stooping down to a level of momentary sexual subservience. She is stepping up to Araragi's level by offering him what he gave her, something that makes a profound personal difference in his life.
And until then she teases him constantly and honestly. "But regardless of how petty you are, I will never abandon you." A teasing insult, but an honest one because it is not a value judgment on her part of Araragi, but more one placed against herself, letting him know that the two are similar, and trusts him to never leave her just as she will never leave him. After all, they are two psychotic virgins whose only shot at social interaction with the opposite sex is with each other, right? (Hey, her words, not mine.)
Senjougahara is a marvelous tsundere. Because the tsuntsun does not cover the deredere. The tsuntsun is honest, and is complementary.
You can find the previous part here.
Edit: A broken PC monitor and a laptop too old to play HQ .mkv files means no pretty screencaps for awhile.