Knowing the amount that should be removed is always an estimate pre-operatively. This estimate is especially difficult from a photo since some women have more breast tissue versus fat than others. That having been said, 1000-1200 grams is probably a reasonable estimate.
It is hard to judge resection weight by a photograph. Size is one factor but density of the breasts will affect resection weight also. Have another discussion with your plastic surgeon about desired size and she/he can tailor the surgery to your wishes. There is a certain amount of tissue that has to come out, the some tissue that is optional. All of it should be sent to a pathologist for evaluation. In looking at your photos, I would guess about 1,000 Gm reduction per side. Good luck to you; it is a wonderful life changing procedure.