Another admiring response from me.
If I was shown this image and told to come up with a word, it's very likely that I would have used the same word as the OP, "serenity." It's an outcome of all the horizontal lines, a perfect reflection that can only happen on a still moment and the subdued colours. The hints of pink and the golden brown centre strip warm the image slightly. It's enough so the photo doesn't suggest cold. Cool, but still comfortable and comfort goes with peace. There's no one element that demands our attention, it's all working together in a relaxed way.
I was puzzled by the bird reference and thought I had missed something. Thanksgiving isn't a big event in Australia. I got there, eventually.