Like it or not, you're mugshot is going to make or break your MSF experience. A happy photo of your face is what people need and want to see. We read so much from a face, especially from the eyes. Remember, you don't have to look like a supermodel, you just have to look like you.
Check the surroundings and background of your photo. Does it look interesting to you? A sunny, leafy glade in the background will work better than a poorly lit office wall. Make your photo appealing in all senses, from your smile to what you're wearing. We see all sorts here (you can imagine!) and know that funny photos, or photos that have a talking point, do best.