The chapter's third and last* mishpat *verse.
Quick answer
Doing right is a pleasure to the person who is right, and the verse treats that as the actual difference between the two halves.
Read both lines
The first line makes justice a joy rather than a duty, which is the whole claim. Two verses have already said the wicked refuse to do mishpat and that treating people rightly outranks sacrifice; this one explains the split from the inside, in terms of what a person enjoys. The second line then supplies the contrast in outcome rather than in feeling, and the asymmetry is deliberate: one side gets an experience, the other gets a result. Read across the chapter's three justice verses, the argument is that the difference between the righteous and the wicked is not effort but appetite.
Related: Proverbs 21:3 · Proverbs 21:7 · Proverbs 10:29 · Proverbs 13:23
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.