Comment 1 for bug 1077188

This type of event-driven update from the backend does not currently exist in Horizon. That is the subject of these blueprints:

https://blueprints.launchpad.net/horizon/+spec/realtime-spec

https://blueprints.launchpad.net/horizon/+spec/realtime-communication

Until such time as those are completely worked through and implemented (looking at late grizzly at the earliest, more likely in the H timeframe given the necessity of coordination across projects to supply the notification events) the way you describe is simply how the system works for changes not initiated from the frontend or which mark a discernable "transition" state on the resource.