What could be causing my breast to be flat on the bottom? (Photos)

Good morning!The flat spot seems to be a thickened portion of the capsule, which cap be released with a capsulotomy. However, lateral to the flat spot there appears to be a little bulge in the fold that represents a weak spot- I would place a couple of sutures in there for reinforcement (the Original Internal Bra). Overall this is subtle capsule work but it needs to be done with a skilled touch!

You have a periareolar incision, putting you at highest risk for capsular contracture. One implant is slightly dropped out, with insufficient upper pole fullness and rippling at the inframammary fold. The other has developed a flattening of the inframammary fold and has more normal upper pole fullness. Although it is not firm or immobile, it is capsular contracture. Although it is not an emergency, if you want it fixed, you should allow a revision specialist do the right thing and use an inframammary incision to correct the problem. 

I would be interested if this was present since surgery. You might just need the pocket expanded in that part of the breast which is a simple procedure.