Inspector look changed

I have no idea what I have done, but the inspector in one of my prefabs simply changed. It is not the first time this happened and it doesn't really bother me or anything, but I am very curious about why and how this happens.

Here is the default inspector in one of the prefabs.

And the "changed inspector"

Also, it seems now I have access to every component and their values within the prefab individually, as if they were scriptable objects.