This is how it can look on the published site:
1. Firstly, choose the Custom block from the block gallery and add it to a site:
2. Hover over the empty column and click on it to add elements, then choose the Image hover in the pop-up window:
... or add the Image hover as an element to some existing blocks:
1. Roll over the element and click on the 'gear' in the top left corner to open the Settings:
2. In the Content tab upload the image or choose it from the gallery:
3. After you set a photo there, you can edit it with some customization options — e.g., applying filter or color overlay:

1. Proceed to the Hover tab in the Settings:
1. In the Hover tab you can adjust the animation settings for the elements and the image itself: