This workflow lets you record dry (clean) while the recorded signal is processed through Eleven, letting you hear it but without committing the track to that tone forever.
The flexibility to audition and compare different settings and combinations of amps, cabinets and microphones is a very creative and powerful tool for mixing and arranging.
The audio that is recorded is the dry (unprocessed) signal only, while playback of the recording is processed through Eleven and any other plug-ins inserted on the track.