Try rewriting this passage using fewer words while retaining the original meaning:
“This limit is surpassed in productive imagination: self-intuition, the immediate relation to oneself such as it was formed in reproductive imagination, then becomes a being; it is exteriorized, produced in the world as a thing. This singular thing is the sign; it is engendered by a fantastic production, by an imagination that shows signs of itself, making the sign (Zeichen machende Phantasie) as always emerge from itself in itself.” –Jacques Derrida
Imagine shit about ourselves, and something happens, but exactly what isn’t clear, mostly because it’s in German.
Imagination crosses a boundary, intuiting the self, how one imagines oneself to be, a thing, which is a sign of the imagined, and so on.
Imagine being a thing or a sign in and of itself.
Now you try it and compare your revisions with mine.