Components are a new thing, and I think the Webflow team is still making adjustments while they settle in to the framework. They’re a big change and a lot of users have had difficulty adjusting to the massive UX changes surrounding them.
I hadn’t even noticed the checkboxes- not sure if those are new, but that looks like a useful indication. I see the Purple property binding reference at the top and the Disconnect, and those are my indications that it’s bound. Also the fact that you cannot double-click edit it in the Component master view.
As to how it happened, I haven’t dug in recently on exploring where Components are at, but at least originally, if you edited an instance element it would automatically create and bind a property, which confused the heck out of everyone.
ALT-DOUBLE-CLICK on the component, or clicking the Edit Component button in the top right corner are the ways to get to the master component.
It’s easy to master, once you know the rules, and I’m hopeful there is some sound reasoning behind all this added UX complexity, like the future introduction of 3rd party packaged “smart” components? Or possibly the ability to build your own smart components using Webflow’s new React development feature set?
I’m just guessing here, but I’ve not seen Webflow invest this much effort in a single part of the platform before, and it just doesn’t make sense to me for the current “instance overrides” feature set alone.