Most AI shopping tools are reactive: they wait for the shopper to open the chat and ask a question. Proactive engagement reverses this. The AI monitors what the shopper is doing — how long they've spent on a product page, whether they've compared items, whether they've added and removed something from the cart — and uses those signals to infer when a shopper needs help deciding. The key design principle is that proactive engagement should feel helpful, not intrusive. A shopper who has spent 47 seconds on a product page is deliberating. A well-timed, contextual message ("Still deciding? I can build you a complete look with this.") meets them at the moment their uncertainty is highest. A generic discount popup that fires on page load is not proactive engagement — it is interruption. Proactive engagement is distinct from exit-intent popups in three ways: it fires earlier (during deliberation, not on exit signal), it is contextual (the message reflects what the shopper is specifically doing), and it offers a genuine service (styling help) rather than a promotional mechanic (discount code).