Well if that's the case - this is really where Universal and Disney start to show their differences. The volcano, from this angle, looks more like a shell covering than it does a rock formation with intertwining slides. While we can make excuses for Universal intentionally doing this so the folks on I4 know it's a water park (like the other slides don't give that away), they at least could of sculpted rock work under the Manta Mat Slides and up into the volcano to give it more of that "blown out look" as
@Disneyhead said.
The thing that really gives it away is the purple support tree that you can clearly see inside of the Volcano - looks incomplete. Now imagine floating down the action river, looking up, and seeing all that.
This comes across as, once again, Universal wanting a Disney caliber product but trying to make it happen on a Universal Orlando budget. As a guy that's good friends with a lot of people who worked on this project, I'll be the first to say that it looks like a total eyesore from the south... and we're only weeks away from project completion. Either make it a park like Aquatica, that shows its bones and accents everything in it with lush landscaping, or go all the way and finish the story you're trying to create. You can't half ass these things - it just doesn't work out... see Chinese knockoff parks as my reference. Color me unimpressed.