I agree. I would continue trying to improve it. Stay with the leaded solder until you consistently get results even better than that.
May I ask a few questions?
– What is your iron temperature?
– How long does it take to heat up to that temperature?
– What is your tip shape and size?
– Are you using flux?
– Are you able to heat both the pad and the pin at the same time?
– Are you able to get the solder to melt without it touching the iron?