This cable is worked across 4 knit stitches, crossing 2 purl stitches with 2 knit stitches.
To create a cable that slopes to the right you slip the first 2 stitches onto a cable needle and hold that needle at the back of your work. Now you knit the next 2 stitches. Finally you come back to the 2 stitches on your cable needle and you purl them.
This is called a 2/2 RPC which means that 2 stitches cross with 2 stitches forming a Right Purl Cross.
Here is a video of this at work:
This is what this stitch looks like when it’s shown in a cable chart. To break down how the stitch is worked you can use this illustration: