Ancient Egyptian symbolism incorporated the idea of scales used on death to judge a person.  The person's heart was 'weighed' and if it was as light or lighter than a feather, the person was free of restrictions and could 'pass on'. This symbolism is derived from both the vibrational frequency of levels signifying lightness or heaviness and the two paths - reincarnation or no reincarnation.

Beyond the Earth level, numerous other vibrational levels exist and increasing rates of vibration are figuratively speaking 'up'. Thus lightness is equivalent to increasing vibrational frequency, if one is 'heavy' with demons weighing you down, then the path in most belief systems is towards reincarnation. If you are not weighed down by demons - which have a very low vibrational frequency - then one is figuratively speaking 'light' and able to rise up the levels and layers and not be reincarnated.

Thus the symbolism is principally connected with the spiritual path.

Any use of feathers in hats, turbans, and so on, thus signified a person who was symbolically free of demons and able to rise' up' towards the Stars.

It is where the English expression 'A feather in your cap' comes from - in essence you are a high flyer!