https://www.vice.com/en_us/article/7kzj8y/why-joe-bidens-virtual-speech-was-so-weird

Joe Biden is not good at technology. The 77-year-old Democratic presidential candidate has been confused by a cell phone ringing, by texting, by Twitter, and by internet law. His virtual town hall was a mess.

While Bernie Sanders was doing near-daily livestreams about the coronavirus pandemic, Biden has been largely absent, leading many to wonder when we were going to hear from him again. For days, sources close to Biden said he was essentially spending several days getting his webcam set up. Specifically, they have noted that the Biden team was "working on scaling up that infrastructure and dealing with the realities of Biden’s Wilmington Home, like the fact that there aren’t particularly high ceilings, which can make lighting a challenge."