How does the Random Song Button in Soundcloud work?

I noticed something with the Random Music Button. Is it possible that it choses a specific Range, lets say the song Number is on 130 in the Playlist does it chose for example Song[100, 160] and choses a song only in between that Range, cause its only hopping randomly in a certain range not the entire playlist, it repeats some songs many times I dont know if that is supposed to be that way but wouldnt it be better to get the range of the whole playlist and get a random number from that number?

Thanks.