Infected incision behind ear? (photo)

Thank you for your question. This is not uncommon. During the early healing period you could develop an infection, or have a reaction to some of sutures used in a facelift. Keeping the area clean and an oral antibiotic can help. A topical solution like Microcyn kills bacteria better than Hibiclens. It takes a full year or more for the subtle healing to occur. Follow your surgeons regime. They want a nice result as well.
Best wishes.

The incision behind the ear appears to be open and not really infected. This is something that should be brought to the attention of your plastic surgeon. He will instruct you in management until the problem resolved.

It does not look infected, but that is difficult to judge from a photo. It may just be some inflammation in the scar as it is healing, with slow healing.  You should ask to see your  PS this week as they can help you get this healing better.