Well now... where is this reality you are referring to, and who else can see it?
Seriously, the Neptune/Jupiter conjunction should give this person a very rich imagination and "otherworldliness" but that doesn't have to be a problem. Over the years I have come to see the two sides of Neptune. Essentially, Neptune's job is to deny the physical world. Some people like to think of the physical world as "reality" but really, it is only one facet of "reality." At its least healthiest, Neptune denies the physoical world through lies, drugs, alcohol and fantasies. However, if you choose a path of meditation and spiritual connectedness, you will also be denying the physical world, but in a far healthier way. The more in tune a person is with the spiritual side of reality, the easier it is to cope with the physical side of reality.
The biggest challenge with this aspect is the opposition. All of the effects of the Neptune/Jupiter conjunction, for better or worse, will be manifested on other people, or other people will manifest them on the person. Without seeing the rest of the chart, just based on this info, I would say steer clear of drugs and alcohol, and try to walk a spiritual path.