This article goes into detail about the image cropping feature
The Image Cropping Screen
How to use
To use the image cropping, you will need to go the image tab on any tile that has the option to add an image. Once on this tab, a new button will appear called edit image. Clicking on this button will open up the the image cropping screen.
Here, you will be able to choose the section of the image that you would like to keep. To do this, you can grab an anchor point on the selected area and drag to resize and re-position. In addition, you will be able to select from three aspect ratios (16:9, 4:3, 1:1) which allows you to be able to lock into an aspect ratio when resizing. To turn this off, all you will need to do is click on the aspect ratio again.
Once you have the area which you would like to crop, you can click the save button. This will ask you to save the image, with a pre-populated name and link based on where you had gotten the image. You will be able rename as well as change the location of where you save the image. Once this has been selected, the new image will populate the image link url.
Note: This saves the image as a .png. This means that any non .png images will be converted into this format on save.