Currently, all the blocks images come from CSS styles. They are placed using CSS font face features (see image attached to this ticket).
We should allow developers to customize the look of blocks element by adding an image from the specified source (inside the <img/> HTML attribute).
On the backend side, we have all required information available. The information about image path is provided within the block config hash/object.
You can reach the required piece of data by using the following piece of code in the view services:

this.get('app').get('config.studioBlocks');