It's a complicated process involving professional heraldics working according to strict guidelines, so that only leaves a certain freedom in regards to the design.
Once the experts are done making a draft, the colors needs to be approved and so does the design. In this case in Denmark as well as Scotland.
Then one of a very few artists here in DK paints the crest.
The crest depicts the marriage between two people. To the left is representing her match to Frederik.
The three blue lions represent Denmark. They are shown twice because Frederik is the son of the Monarch and (crown) Prince to
The polar bear and ram represent Greenland and the Faeroe Islands.
The shield with the yellow and red stripes represent Oldenburg.
The two blue lions represent Slesvig. Northern Slesvig is now a part of Denmark, while Southern Schleswig is now a part of Germany.
The red and white cross in the center represents Dannebrog.
The three crowns on the blue background represents the Kalmar Union, from back when the three Nordic kingdoms were united Margrethe I.
To the right Mary and her family is represented.
The double-headed eagle with the Karac (ship) represents the Donaldson clan.
The two stars represents Australia. (I don't know why) And the rose between the stars may represent Tasmania?
The crest in encircled by a chain for the Order of the Elephant.
And on the outer rim of the rest is a text in Latin: Mary Principissa Daniae Regni Herendis Conjux - Mary Princess of Denmark, married to the Crown Prince/Heir to the Throne.
It took three years to finish the crest.
ADDED: I found the article I translated:
Billed Bladet #20, 2007-05-18.
Her er Marys våbenskjold – Here is Mary’s crest.
- “It’s about the greatest achievement you can aspire to”, says the 27 years old Ronny Andersen proudly, while he looks up at the Knights Chapel (Ridderkapellet) at Frederiksborg Slot. Here Crown Princess Mary’s crest has just been hung up and Ronny is looking forward to see it. Because he designed it, just as he is master of the crest given to her father. The two crests are Ronny Andersen’s debut as royal painter of coats of arms and he has worked on them for a year and a half. During that time the sketches have been presented for both Crown Princess Mary and John Donaldson in Kancellihuset and at Århus University.
- “We thoroughly discussed how the crests should be designed. The Donaldson family has its roots in Scotland and as that is a country with particularly strong heraldic traditions and with strict rules in that field everything had to be in perfect order”, says Ronny Andersen who lives and work in Esbjerg.
Crown Princess Mary received the Order if the Elephant on the 9th of May 2004, fives days prior to her wedding to Crown Prince Frederik and on the same day her father became knight of the great cross of the order of Dannebrog (*). That means that in accordance with regulations royal orders of knights that they must have a crest with their coat of arms and proverb hanging on the wall in the chapel of the royal orders in Frederiksborgs Slotskirke. Crown Princess Mary’s crest is historical in the sense that no crest belonging to a Danish crown princess has been hung there previously, just as it hasn’t got a proverb either.
The writing on the edges of the crests in the Knights Chapel is traditionally in Latin, but as the title “crown princess” does not translate directly to Latin and as there is no precedence among the existing crests, the text ended up being: Mary, Princess of Denmark, the wife of the Crown Prince. Written in Latin naturally. (**)
During the work on the Mary and her father’s crests the wish has been that their coat of arms should be as close to what it would have been in Scotland, but also contain some very personal elements from the Donaldson-clan. That John Donaldson also associates himself with the MacDonaldson-clan was clear at the wedding of the CP couple where he wore the kilt of the MacDonaldson-clan and also in his speech to the bridal couple at the dinner in the evening also referred to the history of the clan.
The red double-eagle, on which a black galley with oars and silver-flag is present on both crests, but whereas Mary in the blue shield-head (top part of a shield with heraldics) has a gold-rose between two seven-pointed gold-stars, her father has the mathematical sign for infinity. A reference to his work as mathematician. The proverb “Ad Infinitium” means “Towards Infinity”.
Ronny Andersen has painted Mary’s crest as an alliance-crest with the crest of the Crown Prince, for which there is a tradition in regards to women who have married into the DRF. The coat of arms is crowned with the special crown-prince-crown specified by Christian V in 1693.
Crown Princess Mary’s crest is hanging between the crests of the Crown Prince and Prince Joachim. They got theirs on the 14th of Fabruary 1972 on the day their mother was proclaimed Oueen of Denmark. Above their hang the crest of Prince Henrik and on top the crest of Queen Margrethe.
Written by Anna Johannesen.
A little explanatory not for those who are unfamiliar with the fascinating but also pretty complicated subject of heraldic.
A crest: The entire thing hanging on the wall.
The shield: The painted shield inside every crest. The painting, also called a coat of arms, served as an identification and gave everyone an overview of your family relations. These paintings would also be on a coat worn above your armour in battle. Hence the word: coat of arms.
(*) Do feel free to correct me if the translation of the title is incorrect.
(**) Mary Principissa Daniae Regni Heredis Conjux Die IX Maji an MMIV.
Sorry my scans don't go that far back. But here is a partial view of the entire crest: https://www.kristeligt-dagblad.dk/si.../10/224794.jpg
Perhaps someone can dig up an HQ pic of the entire crest?