This is not a typical fight scene.
Usually, the camera would be up close and personal, highlighting the violence, the immediacy and danger. The camera would follow people as they got flung around, cutting frequently for stunts. It would be fast.
This is not fast.
This is also a common shot composition for Castiel.
Cas frequently gets very empty shots, where the camera will be pulled much further back than expected and his height will be half or less of the frame. There’s plenty of other things in the frame with the scenery elements, but this is video. The subject, the moving parts, are very isolated.
Emptiness makes an image feel lonely, can make it feel slow or contemplative, increases emotional distance, and highlights otherness.
In this case, the immediacy of the fight is drained. The events become something to be hidden, especially with how the scenery somewhat obscures what’s going on.
Take a look at the second image; with a close view, removing the sword and looking around would be scouting for more enemies. Because the camera is pulled so far out, it takes on a tone of making sure nobody saw what happened.
Cas gets this type of shot far more often than any other character because of the otherness, but in this particular case the meaning is doubled; he is both inhuman, and very different from how he used to be.
Another good example of when this type of shot is used is in 4x16, On The Head of a Pin. Any time something causes Cas to question his orders and the rightness of the cause, the camera pulls away. He is thinking, and the events are causing him to question what he knew, to be cast adrift and feel lost, to feel disconnected from his purpose. It happens most noticeably three times:
1. Outside of the room where Dean is currently torturing Alastair
2. Under the streetlamp talking to Anna
3. Inspecting where the devil’s trap went wrong and released Alastair