The animations show the total of people who are or have been infected in each county/state. This makes clear where historically most people have been infected and how things are changing over time.
The height of the county/state shows the infection rate (e.g. 1 person in 100) as indicated by the color and the legend. Even though the infection rates vary greatly between states, I used the same scale for easier comparison.
I normalized things with respect to population because I think that shows the impact the best. I would assume that healthcare capacity increases roughly linearly with the population. Thus, when there is a high number of people infected per capita the healthcare systems in those counties are likely very strained.
I will try to keep these updated daily for the foreseeable future.
The data I use is collected by The NY Times and published on GitHub at: https://github.com/nytimes/covid-19-data.