Finder may not be directly responsible for this, but it appears that OSX crawls my filesystem and indexes all of the images, music, movies, and whatnot that it can find everywhere. It is represented in the "All My Files" location in Finder where it has various categories for all of the files it has found somewhere in my home directory.
For various reasons, I wish for this behavior to stop completely. If it can't be stopped completely, though, I can live with simply removing these inconvenient previews from Finder and allow the index to sit unused somewhere on my disk (though, I'm sure it's taking up precious space).
OSX Version is 10.10
Here is a picture of the sections that I am referring to in Finder. I have circled points of interest to draw your attention to my specific example of images. Less than 20 images are in actual Pictures folders or whatnot.. the rest are in my system from git repos and whatnot that contain content that I will never wish to surf through from Finder.
Best Answer
You can't stop it from indexing by file type, but you can by location.
System Prefs > Spotlight > Privacy
Any location you drag to there will no longer be indexed or appear in search results.