If you are concerned about the 8 calorie difference, those may due to some other activity outside the workout app.
To see the total calories burned for the day first, tap on the Activity app (and History at the bottom left corner if not already selected - then select a day). Then swipe left in the "Move" section to not show the graph and show the Active and Total calories. (Swipe right to return to the graph.). Or, you can use the Health app - tap on Activity.
According to What is the difference in "active cal… - Apple Community
Total calories include - basal calories + calories burned when doing a workout. Active calories are those that are burned during some activity like swimming running or anything else where your body is moving, Basal are those that your body burns during a day without any activity.