Joe Bidens' "inauguration" was shot well in advance. Music and sound FX (audience, mic echo - spatial, et.c) were added in post. The capitol being 'walled off' was not only to establish the military/NG presence and effectively set up a 'prison'… but primarily to prevent people from witnessing that no inauguration happened on the 20th.

Case and point - was Biden's mental health worse BEFORE (debates, interviews, etc) or AFTER/DURING inauguration?

Use to work in Hollywood and I understand these techniques… and they are much better now.