Dynamic semantics provides a mechanism by which information and discourse referents are introduced gradually into context as a discourse unfolds. Dynamic semantics involves left-to-right evaluation: discourse referents must be introduced before they can be accessed. (E.g. Johni entered the room. Hei began to sing. vs. *Hei began to sing. Johni entered the room.) Anaphoric relations also depend on the local contexts introduced by logical operators; for example, pronominal reference is possible within the local context of nobody but not outside of it. (E.g. Nobody received [a prize]i and bragged about iti. vs. *Nobody recieved [a prize]i. Iti was made of gold.) Here, I argue that a similar dynamic system governs the iconic use of space in sign language. Intuitively, one must create a picture before one can point to it. This dynamic iconic system runs parallel to the grammatical system, but interfaces with it, with interpretation similarly modulated by local contexts. I discuss the interaction of 'dynamic iconicity' with sign language examples involving cataphora and embedded indefinites.