The lyrics are used only for some songs. I used up my premium trial a while ago, and it didn't give me lyrics for most songs. I'm pretty sure lyrics are not part of the Spotify Premium plan. However, you may have heard this from somewhere else, and plus, you are using a different device than me. I'm not an expert on this. But what I can tell you is that you can get lyrics by going on genius. The lyrics you see on the other person's device come from this site. Also, I looked this up. It does say that only some songs have lyrics to go with them.