Smart space technologies have entered the mainstream home market. Most users currently interact with smart homes that they (or an acquaintance) have set up and know well. However, as these technologies spread to commercial or public environments, users will need to frequently interact with unfamiliar smart spaces where they are unaware of the available capabilities and the system maintainer will not be present to help. Users will need to quickly and independently 1) discover what is and is not possible, and 2) make use of available functionality. Widespread adoption of smart space systems will not be possible until this discoverability issue is solved. We design and evaluate ARticulate, an interface that allows users to have successful smart space interactions with an intelligent assistant while learning transferable information about the overall set of devices in an unfamiliar space. Our method of using Snapchat-like contextual photo messages enhanced by two technologies - augmented reality and autocomplete - allows users to determine available functionality and achieve their goals in one attempt with a smart space they have never seen before, something no existing interface supports. The ability to easily operate unfamiliar smart spaces improves the usability of existing systems and removes a significant obstacle to the vision of ubiquitous computing.