Webinar 204 MAF Rescaling - Lamda Command

The academy has the tuner set table 12400 Pwr Enrichment EQ Ratio to a single number for the entire table while tuning for MAF only. In watching the webinar video 204, MAF Rescaling, I noted the commanded Lamda changed from 1.0 to 0.85 during the tuning process.

I'm missing something here......if Pwr Enrichment is set for a single eq ratio (table 112400 GM ECU), what commanded the Lamda to change from 1.0 to 0.85 while conducting the tune (video was tuning WOT above the ~5700 HZ region of the Eq Err scanner log).