When you bootup into pxe, the image does a mini-scan and reports in a very small inventory scan to the core. Just basics like ip address and mac. It uses the inventory scanner built into the WinPE or LinuxPE image. It uses this as the target for the tasks to do the imaging. It doesn't look at the os for a name, it just uses the mac address. Normally if you would install an agent afterwards, it can realize that it is the same machine and replace the miniscan with full scan with the correct name.
Thank you for that answer. That clears up a lot of confusion. I am using WinPE for imaging, which I failed to mention.