If you want a reflection to appear as it does in the real world it should be darker than whatever it is reflecting. A common scenario is the reflection of a sky or a landscape in water. If you're looking at the scene the sky is going to be brighter than the reflected version in the water. This came to mind when I was processing this image. The sunset sky has been significantly darkened, primarily to retain good detail, but also to create a mood. It's obvious the water is brighter than the sky. Clearly not natural. However, I'm not using the phrase "not natural" as a suggestion that some abomination has been created here. It's an observation. How you render tones and colors in your images depends on your intent. If I wanted a more realistic rendering I would have also darkened the water. I decided I liked the balance of the water being lighter because it kept the viewer's eye at the same level as the bench. Thereby creating a stronger sense of looking out over the water. I didn't want attention specifically pulled up into the sky, I wanted the eye to drift out to the horizon.
The way the light was falling on the scene created a vignette-like effect, but this "vignetting" wasn't as pronounced in the bottom right corner. I selectively darkened this area to balance the tones. Here is the photo without the selective darkening:
It's a subtle darkening, just enough to push the eye into the image, not allowing it to linger in the sand. You might have also noticed the color is a little more intense in the second image. I also pulled out some saturation as I thought the sky was a bit too punchy.
I took this photo in the St. Michaels, Maryland area, at a short stretch of beach I frequently visit for sunset. One year I found someone had hauled this bench onto the beach. I couldn't believe it, what a perfect fit for the scene! The next year the bench was gone.
Here is the unadjusted raw file: