well, I'd say he passes up as a Filipino Mestizo because pure Filipinos are darker in general. He also appears to have a sunburn which suggest that he has a lighter skin compared to typical Filipinos. The person also has a squarer face compared to pure Filipinos and his nose and mouth are the facial features that isn't typically found among pure Filipinos.
So it seems his look is rather uncommon among pure Filos?
Pure Filos have flatter nose and wider mouths than him?
What pure ethnic group would he pass better then?
His looks is rather uncommon among pure Filipinos and yes Filipinos in general do have a flatter nose and wider mouth. Hard to tell where he's from with that one pic but I'll guess he's from the steppe.
Would he pass better among Latinos than Pinoys?
Yep you are getting closer to the answer. What Steppe country do you have specifically in mind? I found only one pic which sucks. He is some random dude a photographer took picture of while traveling.