I'm not sure that I'll ever understand the 'big hair' look that Jessica is a fan of. I think that Jess looks so much younger and more attractive when her hair is not styled. Like how she looks here. So you can probably guess that I don't think that she looks her best on her appearance on Ellen in these photographs.
Although her hair does not have as much volume as it usually does, which is a good thing. But it's still too big for my liking.
Otherwise, Jessica is looking healthy and so happy. Her purple/blue dress is really flattering with a v-neck which, by showing off a bit of skin (but not too much), elongates her figure and makes her look leaner. The length, just above her knees, is perfect and the short sleeves would be suitable for most women (especially if you have larger arms as it will hide any wobbly bits). I can't see her shoes, but I'm guessing that she's wearing heels, big ones.