Why is there no article in front of "typical"?
They met one evening in typical New York fashion at a gallery opening
There, fashion means "mode, style, manner". The reference is not to a particular instance of New York fashion but to New York fashion itself, as a mode. When the noun phrase refers to a mode, no article is necessary, and if one is used, it is the definite article.
He likes his BBQ prepared in Kansas City style.
He likes his BBQ prepared in the Kansas City style.
Put your Bluetooth-capable mobile phone in pairing mode.
They stood in silence.
The reference is not to a particular silence but to silence as mode of being or behavior, as manner. They stood silently.