To improve image composition and highlight the image subject, you can crop an item's thumbnail image, the board's banner image, and images in the promotion area. 
To edit images in BuyEx3.0, read this article . 

To crop an item's thumbnail image: 

1. Select the board you wish to edit.
2. Click the Content tab and select the content item you wish to edit.
3. Click the edit icon on the top right of the Select Background dialog. 
4. Use the image cropping tool to define which part of the image is displayed. Cropping is restricted to the item ratio. 

To crop a banner image: 

1. Select the board you wish to edit.
2. Click the Designer tab > Banner. 
3. In the Background Image / Video pane, click Change Background.
4. Click the edit icon on the top right of the Select Background dialog.
5. Use the cropping tools to define which part of the image is displayed. 

 

To crop icons in the promotion area: 

1. Select the board you wish to edit.
2. Click the Designer tab > Promotion.  
3. In the Select Icon pane, click Upload custom item.
4. Upload an image from your computer. 
5. Use the cropping tools to crop the image into a circle, square or rectangle.