The column has gotten wider, so photos can be displayed much larger when you're scrolling through the feed. This actually seems to be a pretty considerable improvement. However, it will be interesting to see if they have to crank up the image compression even more to aid in fast load times. Facebook is already rather unkind to uploaded images when it comes to image quality and color accuracy, so this could mean bigger images (hooray!) that look worse than they do now (boo!). Only time will tell that, though.