Something that is not CPU architecture
My head hurts. Let's look at some pictures.
Here's a picture of our Dothan-based Pentium M 755 CPU. The flip-chip package leaves the chip exposed, with no metal cap to protect it. That gives us a nice view of the relatively small chip, which is situated on an organic package the same size as the one used for Socket 478 versions of the Pentium 4.
This is a side-by-side shot of the underbellies of a Socket 479 Pentium M and a Socket 478 Pentium 4. As you can see, they're vastly similar, with only a pin or two of difference.
The socket on the DFI motherboard uses what looks like a standard laptop-style retention mechanism for the CPU. Instead of a pushing down a lever, one has to turn a screw in order to lock the Pentium M into place.
Finally, here's a quick visual comparison of Pentium M and Pentium 4 coolers. DFI's Pentium M cooler looks to be an all-aluminum affair that's not very heavy, while the Pentium 4 cooler is a part-copper affair with a more complex design and quite a bit more weight.