If you start with You are not allowed to view links. Register or Login to view. there are, at the end of what I refer to as paragraphs one or two glyph-strings that are right justified. Sort of like labels, but just oddly spaced strings for now.
In addition to the plant page you mention there are others where a glyph-string is paired with another near the image or appears to be paired with a vertically aligned block of two or three glyph pairs near the image. Again, sort of like a label.
And You are not allowed to view links. Register or Login to view. and You are not allowed to view links. Register or Login to view. among others show isolated glyph-strings near the plant, in the lower right hand corner on these pages. Very like a label.
I think there is some indication that the text on the page serves two different roles. No proof, but some circumstantial evidence.
If that is the case then the assumed descriptive text is being fitted in around the image and around the assumed label.
If, a word were split, for example half of it on each side of a plant's stem in a drawing, I don't think we would be able to tell. If I write something in English like SPEL LCHECKER you can tell I split a word and you can even tell I did it wrong. If I were to do the same thing to VMS text it's unlikely you could make the same judgements.
I'm unclear on your comment about filling space with random glyphs. Are you saying the spacing indicates that that's not allowed or are you saying it happens elsewhere in the text but not here?