I think that it's a good idea to have a profile picture because it gives a personal touch to your writing. I always find it weird when there's a cartoon or picture of an animal instead of a person in the profile (unless the animal is doing the writing...).
My personal opinion is that a profile picture should be flattering, but feature you as a real person, not a magazine model. When a picture is too perfect, I always wonder if it's real. It's fine to "stage" a picture so that it's shows your best features or includes something that relates to your interests.
By the way, I think your profile picture is just fine...you look like a pleasant guy with a smile under that beard!