of the alternative meaning of the word "dude"

At first I learnt that Xiaxue was a dude after watching Steven's video to Wendy when he called her "dude" (1:40 minute mark). Then I learnt that there is another definition of the word "dude" as explained in wikipedia.

In informal speech, many young people use the word "dude" freely. "Dude" may also be used alone in a sentence, serving as an exclamation; denoting a feeling of surprise, happiness, disappointment, amazement or anger, among other emotions. The word might also be used practically anywhere in a sentence in order to convey such sentiments in conversation.

I know my engrish sucks sucks sucks....