Optical Illusion - auditioning two options

Well, I haven't completed the project yet, but have arrived at a pivot point... I need to decide if I want to use the other two pieces of dyed fabric, or leave the design as is.  I made the passe-partout from black fabric, used some scraps of fabric to cover the inside of the frame, then stitched the pleated piece to the back of the canvas (actually, twill in my case... I used undyed twill and stretched it over some stretcher bars I had on hand).
Below is the pleated piece with the passe-partout draped over the stretcher bars.

In this picture, I laid the 2 other pieces over the bars and under the passe-partout... the fabrics have not been quilted yet.  My dilemma is that I feel like the 3D effect is lost when I put the two pieces on top.  So I am going to study these pictures a little before deciding how I will proceed.

I must confess that I am not happy with the passe-partout, and may need to do a little more work to get the opening to fit over the stretcher bars better... the opening appears to be too large, so I may need to make another one that has a smaller opening, or maybe use a contrasting fabric to make an inner border.  But I am fascinated with this project... it is very different than anything I have worked on before, and I think it has given me a lot to  think about, and I'm sure I will try this again!