[noreasonw]

it depends of the mood of the engineer, if he is trying to solve a difficult problem then you could share his interest in case you are in the same roof for the problem, but he may be tired or thinking there are barrier that he will never be able to jump over and you could exacerbate that sensation if you don't know about the problem.

Perhaps that person has a blog and you can understand what he is doing and what are his goals, that should be interesting. The impression you give depends of what the other person expect from you, are you ready for the work you are supposed to do?