I would say that she has definately lost a little weight and/or some fat. If you scroll down to below picture 1 there are 4 thumbnails which enlarge a little as you roll your cursor over the pictures 2 of them are of her in the pink and 2 of them are of her in the red dress. I will have to assume they were taken around the same time as the 2 main pictures you posted and in those thumbnails you can clearly see her left arm in each outfit and it looks to me like she has definately gotten a thinner arm, around the upper arm area, in the pink outfit.