Why does a mp4 file auto-start on a laptop but not on an iPhone?

Hi everyone. I purchased Xara Web Designer 11 Premium last week. Pretty easy to use! I have been wanting to get away from Flash on my current website. Most of the video that I am now posting are on Vimeo which I embed it into Xara Web Designer...very easy.

I have one mp4 that needs to replaced on a daily basis. I drag the mp4 into Xara Web Designer, and it asks if I want it to auto-start. I click yes. I then check it out in the preview, and it auto-starts. I uploaded it, and checked it out again with same result. However, when I look at the site with my iPhone, the mp4 file will not startup automatically. I have to hit the play button, and there is no image preview.

Here is the link to my site http://shadowandsubstance.com/test/test.htm. Any help would be most appreciated!

Larry Koehn
Clarksville, Tennessee