"I think we're tremendously different than the series, if they were to tune in to the series after seeing the movie they might be disappointed. That there was, you know, that they might have some kind of adverse reaction"

In this quote, Gillian Anderson is talking about the differences in between the motion picture and the series that she is a part of. She thinks that the two are "enormously different" which audiences who have actually seen the movie first might be disappointed if they then tune in to the series. She recommends that this frustration might result in an "unfavorable response" from audiences. This could mean that they might not take pleasure in the series as much as they had hoped, or that they may have an unfavorable action to the differences in between the film and the series. In general, Anderson is acknowledging that there are substantial distinctions in between the two and that this may impact viewers' perceptions and enjoyment of the series.