This is a mildly humorous indicator for a
German of
Polish extraction, although the expression has also been heard in North America, indicating those of a more general Eastern European descent. Depending on the
tone of speech, the word can be used neutrally, somewhat flattering or even somewhat condescending.
At that
fancy restaurant, the server was a typical Deschi. He had that
suave walk to him, a slightly reserved posture and a somewhat terse speech - but always courteous and friendly without acting overly subservient.