https://qagg.news/?read=3234 "Find the reflection inside the castle" Pics of Biden "OO" from Google Image search "biden oval office":

cnn https://dynaimage.cdn.cnn.com/cnn/c_fill,g_auto,w_1200,h_675,ar_16:9/https%3A%2F%2Fcdn.cnn.com%2Fcnnnext%2Fdam%2Fassets%2F210120181235-biden-wide-shot-oval-office.jpg

abc: https://s.abcnews.com/images/Politics/biden-ovaloffice-01-ap-iwb-210120_1611258717228_hpMain_16x9_1600.jpg

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

fox6now: https://images.foxtv.com/static.fox6now.com/www.fox6now.com/content/uploads/2021/01/764/432/GettyImages-1230701139.jpg?ve=1&tl=1

reuters: https://s3.reutersmedia.net/resources/r/?m=02&d=20210123&t=2&i=1548779747&w=780&fh=&fw=&ll=&pl=&sq=&r=2021-01-23T011713Z_33362_MRPRC2YBL9RX2O7_RTRMADP_0_USA-BIDEN-INAUGURATION

...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