How quickly would there be signs that the nipple had died after breast lift surgery? (Photo)

Yes, you appear to be healing very nicely; there is no evidence of compromised blood supply.   Generally, compromised blood flow comes clinically evident very quickly (within one to two days) after this type of surgery. Best wishes.

If the blood supply to the nipples was compromised, the skin wound turn blue/purple/black.  Since your nipples are nice and pink, you are fine!Good Luck!