I used the Greek letter Sigma as a symbol for the brand.
"In mathematics, summation (capital Greek sigma symbol: ∑) is the addition of a sequence of numbers; the result is their sum or total." https://en.wikipedia.org/wiki/Summation
Sigma/Summa has similar meaning to 'en masse' as it represents a whole, a sum of parts etc., plus it also looks like the Latin letters 'E' and 'M' which are the initials of 'en masse'.