Historically, armies weren't really known for their stealth. A couple thousand soldiers marching together, with trumpets, drums, banners, and all other sort of kit doesn't generally go unnoticed by others. In fact, they'd make it a point to stand out. Maybe by putting on a big, flashy show, the enemy would surrender, or at least not fight as well because of intimidation. Well, now your Sigmarite forces for Age of Sigmar can get some of that pomp and circumstance.
As you can see, they've got both a trumpeter and a banner bearer. So your enemies will know you're coming to bring some holy vengeance upon them. There's also Chamber Command set you can get that gets all of the new HQ-type options in one place.