Triangle-shaped Belly Button After Hernia Surgery

Your belly button certainly looks triangular at this time, but there is still evidence of ongoing healing; there's clearly skin discoloration consistent with bruising and your skin and soft tissue appear swollen. As the swelling and bruising go away, it's possible that your belly button may develop a more normal shape.
If, at least 6 months after your umbilical hernia repair, you still have an abnormally-shaped belly button, you' may be a candidate for an umbilicoplasty. This can often be performed under local anesthesia. It would entail making new incisions around the stalk of the belly button and re-insetting it to the abdominal wall skin, to give you more of an oval or round belly button.
Best of luck!

Usually, hernia surgery is on the lower half of the belly button. This area is sometimes fixed by the scar for a period of time. Ask your surgeon when you can start to massage the scar. Massage will usually help this change resolve.

I share your concern but time is a great healer.
For the time being, the tissue is still healing and the process will go on for 6-8 months. To influence scarring, if the umbilicus would let you, you may want to see if you can put a round marble in there which will essentially stent the walls and direct the walls to scar in a more circular fashion.
If the result is not to your liking in 6-8 months, I would consult a plastic surgeon (check www.PlasticSurgery.org for listing).
Dr. P. Aldea