Quoted from zucot:
Perhaps the 'old' faces look difference because they're lit and you're seeing the texture of the inserts that they're screened on?
I was wondering this too. But I agree with Aurich that based on the pics alone, the character photos stand out more now from the hand-drawn art than they did in the original playfield design. Bummer, but that's the deal when you work under a license.
Removal of the pot leaf is no biggie to me and probably even an aesthetic improvement. A smoldering joint would have made much more sense (and would be missed). The stylized pot leaf has more of a late 70s feel to me, and The Dude definitely still has one foot in 1969. It's an iconic image, but just doesn't quite work with The Dude's character (he's a fan of the stuff, but it's not like he would ever wear a pot leaf t-shirt). Now if we were talking about a Dazed and Confused pin, you'd need that leaf!
Swapping the gun for the crowbar next to Larry's car seems like an improvement to me -- a useful visual cue to remind you why the car is on the playfield at all.
And I agree that the dream-sequence bowling ladies look better now.