If you are having a conversation but are more engrossed in your phone than in the presence of the other person, the other person may feel uncomfortable or uneasy about whether you are listening to what they are saying. Even though you know in your head that you should not do it, there may be moments when you end up looking at your phone when there is something on your mind, or you look at your phone out of habit even if the content is irrelevant. Here is a free illustration of a woman who looks at her phone even when she is talking.