I still have to wonder about my theory though. Take this article for example:

http://www.fontsite.com/Pages/Features/T1vsTTa.html
Technical Differences

The first difference between TrueType and PostScript fonts is their use of different sorts of mathematics to describe their curves. Conversions between the two formats are typically imperfect: although mathematically speaking the quadratic B-splines of TrueType are a subset of the cubic Bézier curves of PostScript, there are usually small rounding errors no matter which direction one converts fonts; however, the errors are greater in going from PostScript to TrueType than vice versa. More importantly, hinting information does not directly translate in either direction between the two formats.

Some how the "mathematical" information that tells the computer how to display the font has to be included in the image. I'm just thinking hypothetically, but how else can you explain it? A computer isn't going to "see" the graphic. They are going to see the code.

So in other words we see this

http://www.fontsite.com/Media/T1vsTT/Head.gif
The computer sees this

http://www.boastingrights.com/ozzu/image.html
So it has me curious, what this site is doing to interpret the code in the image.