Give Lightboxes the ability to be re-engaged

We compete with Attentive for lightboxes. Customers want to switch to us from Attentive, but are hestitant to do so because Attentive offers the ability to re-engage a lightbox whereas we do not. When a lightbox is closed out, a companion-like icon appears in the bottom right of the screen that when clicked opens the lightbox back up. Screenshots attached.