Let's travel back in time, around a year before this article - about the first stamps of King George VI -, when the British Post Office was working on the three projected series of the new King Edward VIII.
Published obviously by the Great Britain Philatelic Society, this 1974 fascicule by A.J. Kirk is already ancient (understand: only the publisher has got some unused items somewhere in the stockroom - sending is efficient) but flourished with illustrations. The author told first the genesis of the only four stamps of the reign of Edward VIII. A short reign, ended by the future Duke of Windsor to marry a divorced woman (an abdication that let him express all what he thought about European politics in the 1930s... expressions that won him the friendly post of Governor of the Bahamas, directly proposed in 1940 by Prime Minister Winston Churchill. The article of Wikipedia in English told of menacing the Duke of being court-martialed that may have helped).
The series was issued in September 1936 for the Royal Accession of January (8 months and some days vs 6 months for the urgent George VI series). Then, it would have been two series: one for the coronation in May 1937 and one definitive ones. The projects reproduced in the book present the King in all kind of military uniforms, with all sort of ornaments. Edmund Dulac and the president of the Scottish Philatelic Society proposed for the first time (and again for George VI) their ideas with the flowers of the four parts of the United Kingdom. The crown was omnipresent.
Until the unexpected arrived: a 18 year old fellow ask if he can propose a project. He was thanked by the Greater Post Office for his ideas. In return, after he discovered the final design of the stamps, the father answered politely that the GPO may not have been honest in this story. I let you compare the designs...
With a 20 page long and illustrated specialized study and in consequence of the abdication, the genesis is quite short. But, all the reproduced projects show that design ideas for the series of the next decades were in place: use of sculpted profile, castles and monuments for the high value definitives for example.
Have a nice reading.