What could help smooth this area out? (Photo)

You have excess perineal skin and anal skin tags which can be excised in an office setting under local anesthesia. This could have been done at the time of your labiaplasty, but there's no problem in addressing this now. The goal is to have a smooth perineum and anal region.
Go to the link below to see hundreds of before and after photos where you will find many examples that are similar to you. From that link you can schedule a virtual consultation via phone or zoom, at which time we can discuss in depth your anatomy, expectations and concerns. Women from all over the world travel to my Center for their Intimate Makeover.
Best of luck,

The area of the vulva you are referring too is the posterior commissure. This excess skin can be removed by performing a small perineoplasty. Another option is ablative therapy via “feathering” were the tissues of concern are vaporized into smoke and new skin grows in its place resulting in smooth perineal skin. Best of luck! Davis CA
Dr Michael Reed @thecosmeticgyn

Your labiaplasty should have included excision of this loose skin. Since it wasn't done, it can be done now. It needs to be done with precision to avoid pain issues afterwards. There is no unusual connective tissue in this area and there is nothing risky about it in experienced hands. It shouldn't require a perineoplasty, but that's an option to consider if the vaginal opening feels loose during sex.

I agree with Dr. Reed, my former trainee. It is not rare that when performing a labiaplasty, especially via a "linear/trim" technique, that the surgeon is not sure how to handle the lowermost portion of the labia, especially if the redundancy involves the area at the posterior vaginal opening. Your revision, if performed by an experienced surgeon savvy in working around the posterior commissure, should well accomplish what you wish. I see you live in Phoenix. My suggestion is that you visit websites of surgeons in your area to see if any have multiple "before & after" photos specifically showing posterior commissure work. You may have to "travel" to find the right person, but only a short distance. In addition to Dr. Reed in Davis, CA, I have trained Dr. David Ghozland in Los Angeles, and of course I do this work in Sacramento. All of us are a short plane ride away, and are set up to accommodate "out-of-town" patients. Our fees are similar. Check out websites & photos, and RealSelf's link below... Best wishes, Michael P Goodman, MD, FACOG, IF, AAACS. Revision Surgeon, Sacramento, CA, USA