Bingowings said:

I have to disagree there.

The difference is down to design not in universe plausibility.

I remember seeing AOTC and being rather taken with the opening scene of a giant chrome wing landing on foggy Coruscant.

The Star Destroyer is a piece of military brutalism.

It's matte clustered detail lends it a sense of massive scale.

The Naboo ships aren't from that same design ethic.

They are meant to look light and shiny and they do.

A VC10 looks just as other worldly :

One may argue that the resolution of the digital medium and the computer model get in the way of selling the model itself but the idea is sound and plausible.

Honestly, the "clean" designs of the ships in I and II are one of the best ideas from the Prequels. The Prequels should also be DIFFERENT from the PT guys, remember?