Looks viral with those distorted leaves.
Could be viral- one never knows.
However, I do know that variegation frequently distorts leaves.
and I would like to think this is dna based variegation based on the broken flower color and the speckled effect.
Here is a chimeral based variegation from last year showing some leaf distortion.
Petunias are commonly affected by the same mosaic diseases of tomatoes, potatoes, etc. The mottled leaves and petals and stunting are typical symptoms of viral infection though there are other physical symptoms, as well. It's interesting, though!
Here is my chimeral petunia after the variegation began to stabilize. Unfortunately, the variegation was a little TOO severe for adequate sun tolerance.
Here is a new petunia for this year.
The effect is somewhat subtler, though this may lend sun tolerance.
The pattern is pretty regular and unique with each leaf having a thin dark edge and then a thin light border just inside that. However, there is distortion. Always a trade off, I guess.