Robert Walser made use of the miniature form in his Microscripts — tiny embodiments of the miniscule.  The microscript form came to Walser as a result of a writer's cramp, which he qualified as: "a swoon, a cramp, a stupor - these are always both physical and mental."  His formally ornamental scripts turned tiny, microscopic, using pencil rather than pen, breaking with what translator Susan Bernofsky calls "the aesthetic ideal of the elegantly inscribed page." 

The Microscripts are written on found materials which make the texts look like collages, modernist mashups toeing the line between mechanical and personal production.

In English, the gloss is often taken as a form similar to the interlinear gloss of medieval text or marginal comments (as one sees in Coleridge's the Ancient Mariner). In the introduction to Robert Walser's Microscripts, translator Susan Bernofsky describes the satirical gloss as a well-known form in German literature, popularized by Karl Kraus. One thinks of Robert Musil—who loves them – and Walter Benjamin, who seems to be influenced by them.

W. G. Sebald called Walser "the clairvoyant of the small," and Walser took this smallness literally as his handwriting got smaller and smaller over the course of his career. He even squeezed out a final short novel, The Robber, on 24 sides of octavo-size paper in what scholars believed to be a secret, uncrackable code.

Nothing remains from Walser's final years in the institution, the asylum where he died and disappeared.

Here is one of Walser's microscripts as translated by Bernofsky.

Maira Kalman’s illustrations and notes are also marvelous, and they exist in dialogue with Walser’s biography. They are captions for glosses—-or glosses on images.

The gloss form is still fantastic, and it’s defined as a brief notation, especially a marginal one or an interlinear one, of the meaning of a word or wording in a text. It may be in the language of the text or in the reader's language if that is different. Here is the wikipedia:

A collection of glosses is a glossary. A collection of medieval legal glosses, made by glossators, is called an apparatus. The compilation of glosses into glossaries was the beginning of lexicography, and the glossaries so compiled were in fact the first dictionaries. In modern times a glossary, as opposed to a dictionary, is typically found in a text as an appendix of specialized terms that the typical reader may find unfamiliar. Also, satirical explanations of words and events are called glosses.