Yeah, it's possible. One problem is that with the current banners, that have a symbol pretty much center of the banner, it would not be possible to display it on the chest in an acceptable size without seeing a seam at the bottom of the armor. The screenshot was clearly taken with a special banner that has either a very small symbol, so that the banner can be stretched to cover till the bottom, or with a banner that doesn't have the symbol dead center, but in the upper half.