You can crop and edit images when creating new ads. After you have uploaded your images on the Create Ads page, click on the individual images next to Adjust Crop to open the Editor.
To crop the image, click and hold anywhere on the red box, and move your mouse. The darker area is the area that will be cropped from the picture. You can also move the selection to the area of the image you want to display simply by dragging it around the image.
You can also adjust the Hue, Saturation, and Brightness by sliding the bars to the left (to decrease) or the right (to increase). Click Reset Filters to set them back to their original settings.
When you have finished adjusting and cropping your image, click Save.