I'm all about separates, so I usually add a piece or two each year - sequins, velvet, etc., and remix. Regarding photos, I don't think I would be too concerned, myself. Then again, I am tall, so would be stuck in the back row and mostly hidden anyway. Unless the outfit is significantly stand-out and unique, would most people notice if it were repeated? And if they did (and in a catty way) that speaks more about them, I think.
I think the lbd is so fantastic on you, a true classic. Others have mentioned a statement necklace, velvet choker, and/or glitzy stockings/shoes to mix it up. Would you try a hair piece like a fascinator or blingy headband? Or some waist detail like a sash, ribbon, or thin metallic belt? Or make your wrap a bold swath of satin - magenta, turquoise, etc?