Where the hell do they get clothes that have their cutie marks on them?? Like its from another dimension... the likelihood that they would find garments with their other world designs on them is extremely low if not impossible.
How did they get, why, what significance are the symbols to them. The films answer none of these and the marks are only there so little girls can recognize their favorite character.
What do you know? Haven't you heard of suspensino of disbelief
You are if you think the characters in eqg have a legitimate reason to wear those marks on their clothing other than so little girls can recognize their favorite pony in the movies. There is no reason for the characters to have them in eqg when we are given no reason to why they wear them. People in real life don't have special symbols that represents them except for companies and some artists. They need to explain the significance of the characters wearing those marks on their clothing for it to be anything more than lazy writing. In the show the characters have their cutie marks because it represents who they are and they receive them when they become conscious of their special talent/purpose in life. In the eqg all we know is that they have the marks because their pony counterparts have them