One big difference, and one that I had been hoping for, was the fact that the desert was in bloom: lots and lots of flowers. Here are a sampling of what we saw (hopefully identified correctly - if I've gotten any of them wrong, PLEASE let me know in the comments):
Fragrant Evening Primrose
Flowering cactus - possibly prickly pear?
Another flowering cactus - possibly prickly pear?
Another kind of primrose (?)
Claretcup - spectacular in person
Hopi Blanket Flowers, maybe (?)