This data was exported from two iPhone users during 2017 and January 2018. The data was collected by the Health iOS app that tracks the number of steps taken per day by each user.
The plot shows that in general Emily is more active than Chris. Using the brush to zoom in will show Emily is more active during the week and shows lower activity during the weekend. Chris has several periods of low activity that coincide with the weekend and a couple smaller spikes during the week.
Use the brush to zoom in on the very large spike around May 1st. This high area of activity coincides with a trip to Italy. Emily and Chris did a lot of walking together to all the same places. However, Chris's steps are always just below Emily's. This could be because Chris is taller and needs to take fewer steps than Emily. A few other similar spikes can be seen throughout the year when they travel together.
Hovering the mouse over the plot will display the number of steps each person took on a particular day.