Cropping Thumbnails: Make the thumbnail look the way you want
Some of the images we use look fine in the Page or Post, but if they need to be sized as a Thumbnail, they may not look as good. Thumbnails are basically created from the middle of the image.
If the image is a portrait, and there is a lot of image below a person’s head, it may chop off the top of the head. This obviously is not good. To compensate for that, we can Edit our image to make the Thumbnail look better.
If you are just fixing a thumbnail, click on Thumbnail in the Apply changes to: section.
To move the box release the Shift key and place your cursor inside the box you created. You will see a four headed arrow and you will be able to click and drag the box to the area you need.
Once the selection is the way you want, you will need to click on the crop button located above the image as shown here.