Coffee, I lived in LA, which has a huge Asian demographic, and also went to a high school with around 70% Asians (ABCs -- American-Born Chinese). If it helps, no one calls them East Asians, just Asians. ABCs actually look different than Fobs (Fresh Off The Boat--and yes, these are slang terms that are commonly used within the community). I'm not sure what it is, if it's just they dress differently, style their hair and makeup differently, though I'm sure that has some to do with it, but you can tell physically which ones are new to the country and which ones were born in the US. To me, the face actually looks different, though I can't pinpoint why. I would probably mention some mannerisms or clothing (though the hoodie is good) that are more American than Asian.