https://qagg.news/?read=3234 "Find the reflection inside the castle" Pics of Biden "OO" from Google Image search "biden oval office":
usatoday: https://www.gannett-cdn.com/presto/2021/01/21/USAT/302c24f4-ee23-4eb0-977a-60c82a33b3c1-Biden_Oval_Office_Decorations_01.JPG?width=2560 realtor.com: https://rdcnewscdn.realtor.com/wp-content/uploads/2021/01/joe-biden-JIM-WATSON-Contributor-1.jpg
...and others. Clearly, the strong rectangular light reflections on the windows aren't from street lights, but match studio lights from a film set. For some reflections and angles you can make out the black parallelogram around it, which matches the casing of a studio light.
Edit: obvious in this one https://thehill.com/sites/default/files/bidenovaloffice_01202021.jpg zoom in for the black rectangles above the rectangular light reflections in the right window
No way they could keep a fake inauguration silent. Waaay too many people involved.