It is very normal for the chin to appear to have more fullness when looking down. It's the reason you don't see "selfies" from this perspective.Some people do like to refine the chin and jawline. This can be a subtle change, but it can create a natural but dramatic looking result. There are many options, including non-surgical options for reducing fullness under the chin. However, nothing is more predictable or creates a more complete change than liposuction. In fact, because non-surgical methods of fat reduction under the chin require multiple treatments, liposuction can often be less expensive. The recovery period for chin liposuction can be very comfortable. It is very important to select a board-certified plastic surgeon with expertise in this surgery. Liposuction is sometimes promoted as an "easy" surgery. In fact, expertise and finesse is required for great results.
It can be very helpful to have some liposuction there. There is always some skin folding when one looks down but it can help. Best wishes