"Garp is seen sitting on a couch next to a person"
After some research a couple of us in the one pace discord think we've identifed this person next to Garp on the couch. It is noneother than Momonga. It was not easy to tell in the original release but a digital color of the scene allows one to see the sword the person has is clearly Momonga's sword from the hilt. Refering back to the original release it becomes apparent as well. The tuft of hair and mustache he sports can also be made out.
Also his striped shirt and pants, also in the black and white 220.127.116.11 00:17, June 13, 2018 (UTC)1SDAN