1 year post-op breast lift. One side is puckered. Do I need a revision? (photo)

You are early on in your recovery. While this issue may need surgical correction, please listen to your surgeon and wait a few months before considering a revision.

Hard to know what is responsible for this appearance. Could be excess skin not removed, overly large pocket in that area or the inferior pocket that could be closed off. The right inframammary fold is lower than the left. Both incisions have delayed healing at the T junction.
Your plastic surgeon is in the best position to evaluate this issue, since he/she examined the footprint of the old implants on the chest wall. If the pocket is open inferior medially, the appearance would be from the loose skin draping from the implant to the medial border of the pocket. If that is the case, closing the pocket to pull that skin in would be helpful.
In any case you have to heal all your incisions before proceeding. It does not appear to be a question of too much skin in that area, because in order to have removed that skin the scar would go even higher and be visible.

At just over 1 mon post op, I would recommend allowing more healing time before making any revision choices. I would wait to see what aesthetics look like at 6-12 mon post op.

I recommend you wait 6 months before undergoing a revision. You may need the scars revised and the implants repositioned for better symmetry,

Best Wishes,

Gary Horndeski, M.D.