First I set up the background.
Then I added some guidelines to help make the rectangle.
Then I used the Rectangular Marquis Tool to create a rectangle along the guidelines.
Then I went to SELECT > TRANSFORM SELECTION
I held down the shift key a dragged the upper right hand corner transform handle 15 degrees of rotation to the right.
Hold the Option/Alt key and drag the upper center transform handle upwards so the rectangle is larger than the edges of the image.
Hit the checkmark or enter to accept the state change.
Fill this new selection with white.
Clear your guidelines.
Duplicate the slanted/angled rectangle 3 more times.
Use the Move Tool to position the rectangles evenly.
Not how the BG can be seen as though there were transparent strokes.
All that's left to do is to add some images above each of the slanted rectangles and add the clipping masks.