How much of the face of a priest in a Catholic confession chamber do you see?
But this is really not about a the specific material that forms the etymological base for the office.
Behind a transenna, things are difficult to picture, and as we will see, this border and opaqueness was intentional for a variety of reasons.:
Latticework is an openwork framework consisting of a criss-crossed pattern of strips of building material, typically wood or metal. The design is created by crossing the strips to form a grid or weave.3 Latticework may be functional – for example, to allow airflow to or through an area; structural, as a truss in a lattice girder;3 used to add privacy, as through a lattice screen; purely decorative; or some combination of these.
But there are pictures employing the symbol:
En skriver i arbejde
–– Ernest Savage: "Old English Libraries.The Making, Collection, and Use of Books during the Middle Ages"
But this is probably misleading.
Since cancelli really just means barrier in the form adopted from old basilicas, now in English called rood screen
You still have this architectural element in modern American courtrooms:
–– Src: Tallahatchie County Courthouse Restoration
–– Caroline Lawrence: "Roman Law-courts", referencing Visualising Late Antiquity Workshop 1, Law Courts in Late Antiquity
In this Court of Chancery you see the barrier, though less lattice-ised:
If you need a lattice:
–– Courthouse: Courtroom
A cancellarius c1710:
The judge’s secretarium was surrounded on all sides by screens (cancellis) to keep out the crowds of people and control their entrance. Basil calls them judicial screens for this reason. Others called them fences (septa), enclosures (caulae), windowed doors (ianuae fenestratae), latticed doors (cancellatae fores). Most were made of wood, but iron, lead, or marble was sometimes used.
–– Aelredus Rievallensis: "Lest the Faithful Should See: The rood screen and its origins in Roman judicial ceremony", Canticum Salomonis, June 8, 2018.
And this type of screen, bar, barrier or even just veil is hinted at here:
As such, I'd say that the desire to see a picture of a really high ranking scribe behind a lattice screen is a bit too anachronistic and therefore not to fulfil. When the office of a chancelier, chancellor came up in medieval Europe the word roots were already sunk into symbolism? The prime office holder was way tpoo busy to engage in any writing that was relegated into a proper scriptorium, chancery or an office.
Chancery or chancellery (Latin: cancellaria) is a general term for a medieval writing office, responsible for the production of official documents.1 The title of chancellor, for the head of the office, came to be held by important ministers in a number of states, and remains the title of the heads of government in modern Germany and Austria. Chancery hand is a term for various types of handwriting associated with chanceries.
The word chancery is from French, from Latin, and ultimately refers to the lattice-work partition that divided a section of a church or court, from which also derives chancel, cancel "cross out with lines", and, more distantly, incarcerate "put behind bars" – see chancery for details.