OK, I am going to go out on a limb here. I could be wrong, but here goes. I vaguely seem to rememberer GE had an automatic extended soak cycle. This was the era of Enzyme Pre-soaks (axion & Biz)and enzyme pre-soak cycles (Kenmore 800 & above, some versions of Maytag Frabric-Matics). I venture to say that when the soak button with the * is pushed and the timer dial is aligned on the 8 minute mark, it does an automatic presoak of filling up, briefly agitating, and then "soaking" for about 30 minutes quietly progressing through the dial and when it got the "2nd rinse" "pre-wash" it resumed with that agitation and then final spin. There could have also been a brief agitation period between the beginning & the last "pre-wash".
I liken this to the KDI18 dishwasher that had full cycle and soak & scrub on the same timer dial. When soak & scrub was selected, the machine did that proper sequence through the timer and ended up with the wash and rinse portions being further along the dial and thefinal rinse ended up within the dry poriton of the full cycle button. Or not so complicated an example, when rinse & hold was used, it did the one or two fills and "stopped" and the timer quietly continued to move back to the off position.