Yogamaya is intuition clubbed with delusion.
From inside, as you proceed in the path of yoga, the more meditations you do, sometimes you get these visions and these visions would be 90% correct. Then you start believing in your own visions and then they all go wrong, this is called yogamaya.
So you should not be too attached to the visions that you get, the psychic ability. In the psychic ability there could be some delusions that mix up and come, that is called yogamaya. And you are a yogi and suddenly some siddhis come to you and you gallop on using those powers or siddhis. Then suddenly you will go down, everything will vanish and that is again yogamaya.
You know the illusion and the ego that comes with yogis, then they become fallen yogis. So that is what is called yogamaya.