Sagging after neck lift. Can a revision improve the look of my neck/jawline/chin area? (Photo)

I would recommend doing the face and neck together for best overall results. You would just need some tightening in the neck using a lateral platysmaplasty. The facelift part will lift your cheeks and correct the jowl fullness. This can be done under local or with IV sedation in the office.

Drains are not necessary in the new advanced minilifts for lower face/neck lifting. That would make it look amazing and is easy to undergo under local. Get it fixed today.

I'm sorry things are not settling the way you would have wished. Yes, we should be able to smooth out the neck by redraping the skin and possibly smoothing out the muscle underneath.
This should be able to be improved.

Much more information is needed such as a full set of facial and neck photographs with your hair pulled back behind your ears, your age, and a copy of the operative report to find out what was accomplished in the first procedure. From the very limited photographs, you could have excess skin, excess fat, either above or below the platysma muscle, or a bulge from your salivary gland in that location. An in-person examination is probably gonna be required to make a determination about how best to proceed.

Given that it's been over a year since your surgery, a revision would be reasonable. It will involve the surgeon freeing up the skin of the neck and jowls and tightening these structures through carefully created incisions around the ears.

Based on your posted photo photos I would recommend a virtual consultation first then possibly offer open revision of neck Lyft with Endo treatment and placation neck muscles. Best of virtual consult with fee $10,000-$15,000