Which component acts as the electrophile in the synthesis of the Sudan-1 azo dye? In the two-pot synthesis, which acts as the nucleophile, 2-naphthol or phenyldiazonium?

Solomons et al. (2014) says that phenyldiazoium is weakly electrophilic. Yet in the questions to be answered in our laboratory manual, it asks for resonance structures on the attack of phenyldiazonium on carbon 1 and carbon 3 of beta-naphthol. 

I'm confused. I can't seem to find a mechanism wherein phenyldiazonium acts as a nucleophile in the internet or in my books.
It was mentioned in the comments but I shall mention it again.

Attack does not have to mean nucleophilic attack. In your case, the attack is electrophilic, the electrophile phenyldiazonium attacking the naphtholate.