They are all very similar, when used to indicate 'look - I have shown you something'. Using 'here' or 'there' would depend on where the action is taking place. 'there' being somewhere away from the speaker, and 'here' being closer. e.g. 'here' would be used to refer to a computer screen we are looking at. or e.g. 'there you go - I told you that car was going to crash'. 'here you are' is also obviously used when giving something to somebody, and 'there you are' could be used to refer to seeing somebody in a picture.