How does Act II, Scene 2 of "Romeo and Juliet" characterize both Romeo and Juliet?
Shakespeare's characterisation is a complex thing: it's rarely as simple as a single answer. And, in fact, what emerges from this "balcony scene" (though, you'll notice, no balcony is ever specified in Shakespeare's text) is the characters' penchant for contradiction and self-contradiction.
Romeo is hugely impetuous, but also hugely shy. One minute he is to speak to Juliet, and announce himself, and the next, he's decided against it:
Her eye discourses; I will answer it.
I am too bold; 'tis not to me she speaks.
So Juliet says she will take Romeo's word, before immediately worrying that he might prove false:
Dost thou love me? I know thou wilt say ‘Ay’;
And I will take thy word. Yet, if thou swear'st,
Thou mayst prove false.
These characters are young, thinking very fast, and prone to constantly changing minds - you can almost feel the blood pumping. Romeo reaches for larger and larger images to try and express what he is feeling:
As glorious to this night...
As is a winged messenger of heaven
And yet Juliet tells him "do not swear". As Juliet, who previously has loved every minute of it, suddenly decides, is their agreement
...too rash, too unadvis'd, too sudden;
Too like the lightning, which doth cease to be
Ere one can say ‘It lightens.’
It certainly moves at a lightning pace. How are they characterised? As nervous, excited, hugely passionate young people in love for the first time.