ImageComments extension by Luke McQuade lets you show images among code in Visual Studio 2010/2012:

Images in code (Visual Studio 2012 with ImageComments)

To add an image you add the specially formatted image comment to your code, like /// <image url=”X:\Path\To\Image.ext” scale=”Y” />. After that the image is displayed by ImageComments right after the comment. You can easily share images with your team by committing them to the repository with the code file and using $(ProjectDir) or $(SolutionDir) macros in the image url to specify relative path for the image. The scale parameter lets you easily change original image size.

While there are some known issues (plus I’d add that images are visible even after the corresponding block is collapsed), the extension adds very useful functionality in a very easy to use manner.

The free ImageComments extension currently supports Visual Studio 2010 and Visual Studio 2012. You can download it, read documentation and see the source code on github.