Not certain I understand this, the y axis is new cases over 7 days, but the x axis is not every 7 days, but daily. So, is the data point at 4/6 is including all new cases since 3/30, and the data point at 4/7 is since 3/31?
Yes. Its a rolling 7 day average so you capture the overall trend. For example reporting is light on Sundays and then on Monday you get basically 2 days worth of data. So it might look like a big dip and and then a big rise. A rolling average smooths that out.