Here are just a few that i have observed. Perhaps others can add observations they've made.

1. Biden did NOT receive a government plane, he had to get a private plane. I dont think that's ever happened before.
2. Inauguration was done in front of no people for the first time ever. To me that makes him illegitimate as his swearing in wasnt witnessed by thousands of people which is the tradition for centuries.
3. His EO's havent been made formal as they have not been submitted to the Federal Register which tallies all the EO's by ever President going back to 1994. As far as they are concerned, he hasnt made any EO's.
4. the YT video for his innauguration has barely passed 500,000 views, and there are more dislikes than likes. this is for supposedly the most popular President in history.
5. there is a photo of NG gaurd troops turning thier back on Biden as his motorcade passes by. As if they dont acknowledge him as President.
6. The Pentagon has not handed intel over to Biden's administration.
7. there are two photos of the Oval Office, one with Trump the other with Biden. they are not the same! the wallpaper in both photos is different. one even shows cars in the background that can be seen through windows, clearly not the actual Oval Office.