Why a miniature?

[lettman]

The attached photo was sent to me by someone whose father finished his WW2 service in the 5th Aust Mechanical Equipment Company. According to Glyde #659, that unit, originally the RAE element of 4th Armd Bde, was reorganised into its new role in October 1944. It's curious that he has used miniature versions of the brigade RAE patch instead of full-size patches, and I wonder if there was any special reason for this, or if he did so because ordnance had simply run out of the large versions.