Thomas Fink is interviewed about his Selected Poems & Poetic Series by Shivaji Sengupta and Natsuko Hirata. You can see this interesting conversation at Dichtung Yammer, but here's an excerpt:
I think that, in much visual poetry, spatial arrangement that departs from the accustomed linearity of free verse influences the reader’s process of meaning-making. In my shaped poems, I solicit the mutual pressure of words’ and clauses’ signifying possibilities and shapes’ constraining and exfoliating tendencies. This also happens in the enjambments and end-stops of free verse, accentual verse, and texts that involve a counting of words per line (something I do), but curves and angles of shaped poems may slow down or speed up a reading process in a different way than these other modes. Except in the “Goad” series, I haven’t intended shapes for series or individual poems to offer referential or emblematic “hooks.” One example would be the smaller quasi-sphere on top of a larger quasi-sphere in the “Jigsaw Hubbub” series which probably encourages a slowing down in the second, longer part.
When I develop a shape or ensemble of shapes for a poem or painting, I tend to read each abstractly. I prefer somewhat arbitrary collisions between the visual and verbal elements. I’m not George Herbert nor was meant to be, and not only from a religious perspective. Of course, when Willem de Kooning was asked whether it was possible at a certain point in art history to paint a face, he retorted that it was impossible not to; any intended abstraction can be contextualized as a figurative construct.