Why do the “doing doing doing” vocals on “Cabinessence” sound so different in acapella vs in the final master?

Have attached a video of the two so y’all can hear the difference for yourselves, but I’ll try outlining the differences here for those who are too lazy to press play/those who don’t hear it.

In the acapella bit (taken from “Smile Backing Vocals Montage”, which is also used in many fan remixes, most notably by Dae Lims and Anonymouse), the doing-doing-doing sounds like a group of people singing. All good? That’s most likely what happened.

However, in the final master (I have linked the 20/20 “Cabinessence”, but you’ll hear the same in the 1993 GV box set and TSS versions) the doing-doing-doing sounds… singular. Idk how to explain it, but it basically sounds like a weird clavinet. Like it’s not sung at all.

This becomes all the more apparent in the higher sections of the vocal part, which sounds like “doing doing doing” in the acapella bit but sounds like “don don don” in the final master.

I have seen nobody talk about this, which makes me wonder if it’s just in my head. What could be the reason for this discrepancy?