Finding Millais' allusions to an anonymous painter is a "bycatch" of my Snark hunt.

[top]: John Everett Millais: Christ in the House of His Parents aka The Carpenter's Shop (1850).
Location: Tate Britain (N03584), London.
Literature:
* Deborah Mary Kerr (1986): John Everett Millais's Christ in the house of his parents (circle.ubc.ca/handle/2429/26546)
p.34 in (01) Éva Péteri (2003): Victorian Approaches to Religion as Reflected in the Art of the Pre-Raphaelites, Budapest 2003, ISBN 978-9630580380 (shortlink: www.snrk.de/EvaPeteri.htm)
* Albert Boime (2008): Art in an Age of Civil Struggle, 1848-1871
p. 225-364: The Pre-Raphaelites and the 1848 Revolution (en.wikipedia.org/wiki/Special:BookSources/0226063283)

[bottom]: Anonymous: Edward VI and the Pope, An Allegory of Reformation, mirrored view (16th century, NPG 4165). Iconoclasm depicted in the window. Under the "window" 3rd from left is Thomas Cranmer who wrote the 42 Articles in 1552.
Edward VI and the Pope (NPG 4165) was, until 1874, the property of Thomas Green, Esq., of Ipswich and Upper Wimpole Street, a collection 'Formed by himself and his Family during the last Century and early Part of the present Century' (Roy C. Strong: Tudor and Jacobean Portraits, 1969, p.345). Thus, when Millais' Christ in the House of His Parents ('The Carpenter's Shop') was painted in 1849-1850, the 16th century painting was part of a private collection. It was sold by Christie's 20 March 1874 (lot 9) to a buyer unknown to me, that is, when Holiday started with his illustrations to The Hunting of the Snark.
Location: National Portrait Gallery, London