If this filter itself is effective, not saying it is, then gaps aren't necessarily a problem depending on where they are and if it still maintains the right pressure/airflow to the filter. Brought up a fume hood because if one of those had a filter for whatever was bad inside, and instead of exhausting outside it went through the filter, it would work still work despite the intentional gap.

I'm not saying the gaps are intentional or in the right place here, but that there could be an ok design with gaps. If you are exhausting through a filter you have to pull in air from somewhere.