Looks better in 97 , more detailed delts much smaller and tighter midsection
The judges care a lot about size and conditioning from behind, this is why Ronnie started beating Kevin all of a sudden. Kevin destroyed Ronnie in 2002, except that he forgot to bring the best back and legs. Ronnie's torso from the front was pretty bad, but best back and legs + conditioning go a long way. Same reason Kai beat Victor at the Arnold. Victor was biger and better in the upperbody from the front but Kai had everything else. Kevin's got great arms in 2002 but Ronnie had the best legs and back combo.
Also I think against guys like Levrone, Ronnie's added deltoid size really helped him, because it balanced out his massive chest and stopped him looking narrow next to Kevin the delt monster! Kevin's delts/arm/chest were never detailed like Ronnie's to begin with so I guess the judges thought Ronnie's added delt size could come at the expense of 5% less detail. Dorian never had grain of detail in his delts once he got to the 260lb range.
Bottom line, the judges clearly felt Ronnie '99 was better than Ronnie '97, hence his perfect score at the O that year.