Sometimes you might have situation that images are not aligned properly in the theme and looks terrible. Specially this happens if you switched to some theme.
To get out of this and fix your all images you will need to regenerate your thumbnails and this can be done with the plugin “Regenerate Thumbnails”
- Download the plugin “Regenerate Thumbnails“
- Install and activate it
- Go to Tools >> Regenerate Thumbnails
- Click on “Regenerate Thumbnails”