None of them. It's a rather idiomatic statement in either language.
The word syne belongs to the noun syn, which refers to the sense of vision, and the verb at syne, which can mean "to appear" or "to examine". So the word has got a connection with visual impressions.
It's a part of a couple of fixed phrases, like this here, and I think "at komme til syne" - to appear (lit. "to come into view") is part of this course, too. The opposite is "ud/ude af syne", referring to disappearance (lit. "out of view").