What does it mean if a guy nods his head up diagonally at me when he sees me eating at the coffee shop?

[Anonymous]

When he nods his head diagonally up at me,it is a very quick and subtle nod.This is the second time he did this when he saw me eating there.I am his regular customer.

Just wondering why didn't he give me a normal nod.

[komotion]

I'm kinda unsure about this one. Sounds like he just had a weird way of nodding. Then again, it may be his way of getting your attention. Stranger things have happened. o_o

[kheserthorpe]

lower left to upper right or lower right to upper left?

[Asker]

He nods at me lower left to upper right. I am sitting facing him on his left.

[heyitsdan]

Its just means "Hey what's up"