If you look at the pattern of the fake tree leaves (willow?) hanging over the moon, they are identical in the pictures purported to be from MK's Mermaid, and from the fan photos from DCA's Mermaid.
This is the same scene, I think that the Disney blog simply reposted a photo from DCA. If you look, the "Kiss the Girl" scene from DCA did have a lot of plain old incandescent light, but it has actually been changed (as the fan photos show), to be more like moon light. Disney recycled a photo from DCA's ride and is selling it as MK's Mermaid.
(Fake MK Mermaid photo really just recycled DCA Photo)
(Updated DCA Fan Photo Mermaid Kiss the Girl)
(Updated DCA Fan Photo Mermaid Kiss the Girl)
I think the only plausible explanation for this to be the same scene on two different coasts would be if the "leaves/branches" against the moon were part of a mural, but I believe they are fake leaves/branches . . .
but a lot of the closer branches/leaves look exactly the same. 99.9% sure this is an old recycled image!