BF1 does not have clan/platoon tags or emblems, but there are 2 areas that two different ones can be used.
The foreground Emblem (funky cat with hands) is the Emblem chosen through Origin client, (edit profile) which takes you to EA.com, and can be a Jpg.
This one shows at end of round.
The Background Emblem (The T), is the one chosen through Companion (View Emblems link visible in image below), like BF4 is a vector creation, and can be pulled in from any BF4 Battlelog Emblems you may have already used.
This one shows on your soldier's actual uniform in the game on the shoulder and on weapons, like BF4 did.
The T looks badass on a gun, because its not in full color but an engraved look.
I'll post a screen when i remember to grab one.