It looks like it is 3-dimensional, practically jumping off the table, but it's actually FLAT! The "depth" is from the differences in the VALUES from row to row, as well as the CONTRAST.
"What is VALUE?" you ask.
It is the Lightness or Darkness of two colors (or in this case, fabrics). The tricky part is that Value is all relative. It depends upon which two fabrics are next to each other.
"What is CONTRAST?"
Contrast is the DIFFERENCE in Lightness or Darkness between two fabrics/colors. There can be High Contrast (BIG difference in the Values of two adjacent colors), or there can be Low Contrast (very little difference in the Values of two adjacent colors).
For example, in the photo at left, the Light Rows all have LOW Contrast among the fabrics - they are all very similar in Value (lightness). In the "Dark" row, there is some Contrast among the fabrics. However, when you compare the "Dark" row as a whole to the Light row, this is what gives you the illusion of DEPTH.
For much more about this topic, please get yourself a copy of Josef Albers' "Interaction of Color." The 50th Anniversary Edition was just published by Yale University Press. It's not a big, fancy textbook; it is meant for you to do the exercises in it and make your own conclusions about color.
I was introduced to this book when I was a freshman at the University of Delaware in the early 1970s, and I have kept a copy of it nearby ever since. It is packed full of ideas for experiments that you can conduct on your own, and some of them are really amazing.
You should try this book if you think you have "trouble" with color!!