Somebody sent this photo to me. I think it is from South America, but I am not sure. In any event, this is a truly beautiful display, and I do not know why they are so seldom seen outside of Tibet. If you know who did this, send a comment. I want to congratulate them.
Usually, you would have a gyaltsen on the center pole. The best ones are the little two or three foot copper ones (gilded), because they won't add much weight. Believe it or not, things like this are a serious engineering challenge, because of wind loads. You can see in the photo below that they have used cloth gyaltsen on the central mast, and lowered the angle of the side flags. This is the common sort one usually sees.
Maybe some people do not honestly believe in the efficacy of prayer flags, thinking them quaint, and giving them lip service... but maybe they don't truly understand the how and why. I think as you get older, you ask yourself why so many highly evolved people spend so much time with prayer flags... I could cite numerous examples but I won't... and eventually you decide, "Oh, well, might as well join in."
That is the wrong way to approach the matter.
You have to involve your heart.
Prayer flags are of actual and in many cases substantial benefit to sentient beings, and by placing as many as we possibly can, we are doing something of a very direct character to help others.