Yellow oozing, what can this be 3 weeks post breast lift. (photos)

Thank you for your question
regarding the appearance of your breasts after your breast surgery.  Definitely
keep in touch with your board-certified plastic surgeon.  Fortunately, if
there is no infection, often times, issues like this heal all by
themselves.  Hope this is information helpful to you.  Be sure to see
your plastic surgeon frequently until you are well healed.

Please contact your surgeon for instructions. In the meantime, I would continue to clean the area once or twice per day. Then cover with antibiotic ointment and a dry gauze to absorb the fluid. If the area opens widely, it may need packed w gauze. Although rare, this type of wound usually heals well with proper care.

Contact your surgeon for an evaluation.  I would recommend you clean the area by irrigating with betadine solution.  This can be done by injecting ( with a syringe)the solution into the hole where the fluid is coming from a few times a day.  This will help irritate the area so it will heal and close from the inside out.  Confirm this with your surgeon and discuss wound healing with him or her.