Well, she could have worn a pair of below the knee “capri” pants. More more flattering, and just as cool in hot weather.
I agree that capris with a stylish top would have been more appropriate. And is she wearing a purple plastic watch? The bigger issue here is she repeatedly has shown she doesn’t much care how she presents herself in public. She knew she’d be photographed but didn’t make the effort to do anything beyond a sloppy ponytail and clothes that I would have tossed in the Goodwill bag long ago. This outfit isn’t even appropriate for the grocery store — maybe it’s a southern thing.
Or a casual summer dress. Or comfortable flats. I’m not angry - she can wear what she wants. But she looks extremely unprofessional. She is not a woman going on vacation. She is 24/7, the First Lady of the United States, the new Jackie O, going on vacation. She should dress accordingly. She looks like she’s been traveling in a station wagon with no air conditioning for 10 hours.