Energy Prospectus

In the Cornerstone Analytics May 2 update they show a plot of "Spot Brent vs. Brent Time Spread" which shows a divergence between about June 2015 to Dec 2015
which they interpret as indicative of a major price bottom. Two questions:
1) Data seems sort of stale,-- wonder why data not shown up to date?
2) What is the "Brent Time Spread"? Seems somehow related to futures market being in Contango or Backwardation but not clear to me.

Ignore Question#1, because a closer look indicates graph is up to date

I'm not sure what that term means. I think it has something to do with the futures strip moving from contango to backwardation. That is just a guess.