Mourning Shield

[L Verge]

Could these be similar to the funeral palls that are placed on coffins by priests (at least in the Catholic and Episcopal churches) as the funeral procession to the altar begins? I thought the purpose of palls was to show that all men are equal under God and, therefore, reduce the pomp of fancy coffins, etc. Could these hatchments or shields have been forerunners (showing the prestige of the deceased) and, therefore, have caused the introduction of palls?? Just a wild guess - I'm good at those.