wordpress 3.6 media manager cropping timestamp

Those new files are your original file resized. When you insert an image and pick ‘medium’ ‘thumbnail’ or ‘large’, they aren’t generated on the fly or pulled out of thin air. They’re created when you upload the image to save size.

The reason you can’t see these in the media section is because the media section does not display files you’ve uploaded, it displays attachment posts, which represent an image and all its sizes.

So you don’t need to do anything to show them, they’re already shown, and you can already choose them, just pick the relevant size

E.g. These are all different sizes of a single image attachment listed on my site:

• http://www.tomjn.com/wp-content/uploads/2013/08/9.jpg
• http://www.tomjn.com/wp-content/uploads/2013/08/9-150×150.jpg
• http://www.tomjn.com/wp-content/uploads/2013/08/9-300×201.jpg