Determining nucleophile vs. Electrophile

[Blake_Katsev_2E]

At the end of class today professor Lavelle described how (CH3)2O is a nucleophile due to the oxygens lone pairs. But for CH3O, the carbon is now an electrophile because the C now gets the full pull of Oxygens pulling power. So C is an electrophile but wouldn't that make O a nucleophile? I am confused on what the overall classification of the molecule would be.

[Monica Habashy 3A]

The overall characteristic depends on the central atom and since C is in this case an electrophile because it is slightly positive, the molecule is therefore electrophilic.