If you are asking a question about a visual effect in a photograph, in addition to posting a sample image or a link to one, it is very, very helpful if you describe your impression of the effect briefly in the title and in more detail in the question.
Short "what is this?" questions have three problems.
First, answerers may not see what you find interesting in the photo, so it's best to be clear about what you're wondering about. Otherwise, you'll get answers talking about other aspects of the photo you may not care about.
Second, no one looking for the exact same thing is likely to ever find this in a search, because there's nothing distinct to key off of. There's no way in Google to distinguish one "what's this effect" from another, let alone in Stack Exchange's own rudimentary search engine. If you describe the image, though, people looking for the same thing have a chance.
And finally, the flip side of that: people who were looking for some completely other effect may stumble across yours, which doesn't help anyone. A clear description will let them skip over it (or know right away that they should ask a separate question).
I know it's hard to put pictures into words, and sometimes it's hard to even know what to say. The sample images are important as well — but please make an attempt at the text.