Each Regiment of the Royal Army has two Colours, (or Flags). A King's Colour, (the more senior of the two), and a Regimental Colour.
Here we see the typical REGIMENTAL colour for a Royal Army Regiment of Foot.
In the 1st Canton we have the Holy Mormoan Kingdom Of New Wales Coat Of Arms:
The Blue Field represents the seas and oceans crossed to arrive in the Newer World.
The Wreath represents "Growth, Fertility and The Land".
The Emu is a native Bird, (and can't step backwards), symbolizing the "fledgling Kingdom advancing swiftly, always with their feet on the ground, and not with their heads in the clouds; and never retreating".
The Crown Represents the Royal Household of Clements.
In the 3rd Canton, (or Upper Fly) we have the Army's symbol: A Lion defending the Crown in a field of blood.
The 2nd and 4th Cantons, (or Lower Hoist and Lower Fly) are two red fields, representing the blood given in defence of the King and Country. The Cross would be in the facing colour of the Regiment. In this case, the Queen Mother's Regiment.
Below is a King's Colour, (again the Queen Mother's Regiment).
The 2nd and 3rd Cantons have the Personal Coat of Arms of King Phillip I. The only difference from the HMKoNW's Coat Of Arms is the three fleur-de-lys, representing his three victories over the French while he was Prince Phillip, and in command of the Army, (more on this later). Again, the cross in the center of the flag would be of the facing colour of the appropriate regiment.