How can i create transparent divs that have a picture as background on an otherwise black background?

Sorry if the title is worded badly.

I want to recreate an interface similar to Windows Phone 10.

You can see an example of what I try to achieve in HTML in this picture:

http://ift.tt/1VW9EBq

The middle tiles act like windows on the baby picture while the space between tiles is black.

Thanks in advance!