1. Line ~#88* typo in source (awsome.png instead of awesome.png).
    Broken links are not only a functional problem, but can also mean that the browser has to download an extra “file not found” page.
  2. Line ~#107* tracking image (beacon.gif) returns a 404.
    See above.
  3. Line ~#36* (imgSearch.jpg) and Line ~#54 (imgsearch.jpg) different casing in src attribute.
    Caching files locally will get the requests served as fast as possible, but the cache is case sensitive so you should make sure all your src values match.
  4. Image ducks.png is a photo and would be better sent as a JPEG.
    Large image files (especially photos) are best saved in JPEG format. The PNG image is quite large at ~135kb. Saved into JPEG format, its size would have been only ~21kb. In contrast, when it is important to have pixel-perfect images, for example, for a screenshot, then PNG files are a good choice.

*Line numbers are approximate.