I love my girls but having them was the single worst thing that's ever happened to my hair - it's totally wrecked. I have gone from mostly-3A-almost-3B-in-places to somewhere in the 2s, with whole sections that are stick straight. I can coax some curls still in the canopy, but that involves a lot of product and diffusing. Like you, the difference in photos is remarkable. I have never in my life worn my hair straight, until a few months ago. I had my stylist show me how to style it straight, because fighting to get it to curl just isn't worth it anymore. I'll probably wear it straight all winter. Oh, and mine started to change almost 3 years ago, and it looks like a permanent situation. Maybe yours is just temporary!
Hair type: Completely confused: mostly 3a, some 3b parts, and even 2 in places; very fine and thin.
Products: Elucence clarifying & MBC; CK, F/X Curl Booster Fixative Gel (when I can find it)