Can't really see (my screen is sort of toasted)- is she wearing pantyhose? Often, for short dresses with long sleeves and no cleavage, that's what makes the difference between appropriate and inappropriate. (Then again, I admit, I'm not a fan of wearing black heels that aren't open-toe with no pantyhose). I think the combination of hair+necklace + sunglasses (for the love of kittens, I ope she won't keep them on indoors!) makes it look a bit trashy. If she had worn the same dress with a tasteful silver necklace, her hair down and tidy or in a tame-looking simple bun and maybe a bolero or suit jacket- the effect would have been deffinitely different.
I know someone who's a graduate student at my faculty- she wears that sort of dresses most of the time (she's got really beautiful legs!), including when she presented research results in an important conference- and I always thought it looks good on her. Not sure how much you can compare the court dress code with academic conferences dress code..