Everytime I've attached photos they have done different things:
1. started as thumb nails -- turned into monsters (pics #27)
2. stayed thumbnails
3. auto-resized
I've been messing with it throughout the day. Now when you upload a photo, it will resize it to 800 wide or 1500 tall and they need to be less than 250k. No more thumbnails, now it's working like the old discussion board.