In this talk, I will make some empirical observations about not-at-issue content in prohibition signs and will discuss their implications for our theories of pictorial semantics and pragmatics. In particular, I will show that some aspects of pictorial representations can be not-at-issue because they are not meant to be interpreted iconically in the first place, while others are iconic, but behave similarly to non-restricting modifiers in language. I will, furthermore, argue that such iconic, but not-at-issue aspects of pictorial representations are, in fact, non-restricting modifiers, rather than some sort of sublexical presuppositions, as their behavior for the purposes of ellipsis/anaphora resolution and alternative generation under 'only' suggests semantic composition. (Note: this is work in progress; the talk will be based on this short manuscript: https://ling.auf.net/lingbuzz/005096.)