It appears that the image sizes I set when creating my posts are not respected when the post is displayed. An example can be seen here:
The images were correctly sized (long edge around 200px or so) so that text would flow around them. But from looking at the post, all the images are taking up the full width of the post area. They’re also squared off, and they’re pixelated because of being blown up larger.
I checked the plugins I’m using and disabled everything except the bare minimums (security, backup, etc). Problem still occurs.