1. If not live, trigger $A (e.g. cycle of promo images)
2. When livestream begins, trigger $B (e.g. screen containing livestream)
3. If stream errors/fails, fallback/trigger $C (e.g. back to monitoring while displaying an "we'll be right back" promo; or back to cycle of promo images)
4. If stream ends, trigger $D (e.g. different cycle of promo images, or different livestream, etc)

Where $A - $D are a variety of possible triggers (layouts, commands, whatever).