Yep! Basically, treat the submission as if it was your a forum post. The editor is similar in a way.
You're free to post additional art or information right on the description box.
Here's a example of me using the feature: https://www.newgrounds.com/art/view/solitonmedic/odyssey
solitonmedic
New update in the art portal! You can set up more then one illustration in one submission now! Kinda like how you could in Tumblr posts now!
mishi-hime (Updated )
How should I use this feature? Should I show detail shots or my art process (Example: http://fav.me/dcu8b28 )?