My first awareness of the term "matrix" was in a math class -- where it means a rectangular array of quantities that are treated as a single unified object. But my online dictionary does not list that definition first; a Google Search using "matrix definition" led me to "an environment or material in which something develops; a surrounding medium or structure." And so it goes.
And when I enter the pair "matrix" and "poem" into a Google Search, the results include poems with the word "matrix" in the title AND rectangular arrays including this one from Eleven Matrix Poems by Roy Lisker and found at this source. Reading instruction includes this:
Matrix poems are written to be read in all of the directions
indicated by their accompanying diagrams.
|"RESIST" by Roy Lisker|
My favorite line is shown as the second column; which is yours?
Fight Ever Will To Never Evade
In closing, one more remark about the Google Search I performed using "matrix poem"; as with many Google searches there was a link to images, and from that I found a delightful array of word-diagrams such as the one above. Try it sometime!