Image has the following properties:

- Has an intrinsic size that is large enough to be noticeable,
  but not so large as to potentially break the layout of a page
  the image is embedded in: 50 x 50 pixels.

- Scales to completely fill any size rectangle so that it can stand in for an
  image of any explicit size or aspect ratio.

- Is a vector image so that its scaled version looks smooth and crisp.

- Has a noticeable color: bright red.

- Has a error-like symbol that is recognizable even if the image is stretched
  to a different aspect ratio: an X.
