Why 7-min video for this?
In backwardation, we compare the future price with the CURRENT spot price and see that future prices are lower (generally because it has been oversold - happens when suppliers believe that prices are going to decline)
No normal backwardation, we compare the future price with the EXPECTED spot price. As you might know, some would argue that future price should be unbaised indicator of EXPECTED spot price; however, deviations always exist. Because of so, the EXPECTED spot price will differ from future price and when the future price is below EXPECTED spot price, then we are having a normal backwardation
Hope this makes it clear
OA