This is the definition of superficial from OALD:
not concerned with anything serious or important and lacking any depth of understanding or feeling
What does concerned with mean here? There are four senses of concern from OALD I find that all seems to be appropriate to the context:
1 [often passive] concern somebody/something to affect somebody/something; to involve somebody/something
- Don't interfere in what doesn't concern you.
- The loss was a tragedy for all concerned (= all those affected by it).
- Where our children's education is concerned, no compromise is acceptable.
- The individuals concerned have some explaining to do.
- To whom it may concern … (= used for example, at the beginning of a public notice or of a job reference about somebody's character and ability)
- Everyone who was directly concerned in (= had some responsibility for) the incident has now resigned.
- Please pay attention because this information concerns all of you..
2 concern something (also be concerned with something) to be about something
- The story concerns the prince's efforts to rescue Pamina.
- The book is primarily concerned with Soviet-American relations during the Cold War.
- This chapter concerns itself with the historical background.
- One major difference between these computers concerns the way in which they store information.
3 worried and feeling concern about something
- Concerned parents held a meeting.
- concerned about/for something The President is deeply concerned about this issue.
- concerned for something He didn't seem in the least concerned for her safety.
- concerned (that)… She was concerned that she might miss the turning and get lost.
4 concerned (about/with something) interested in something
- They were more concerned with how the other women had dressed than with what the speaker was saying.