The video demonstrates how to do the two stitches used to make the raspberry stitch, which are purl 3 stitches together, and knit 1 purl 1 knit 1 in the same stitch.
To purl 3 stitches together, simply take the next three stitches on the left needle at the same time and purl them together as if they were one stitch. You are basically taking 3 stitches and making them into one stitch.
The knit 1 purl 1 knit 1 in the same stitch is done as follows: knit one stitch as you normally would but don't slide it off the needle; move the yarn to the front of the work and purl one, again without sliding it off; finally move the yarn to the back, knit one stitch and slide it off the needle.
These two simple stitches create the very attractive raspberry pattern.
Want to master Microsoft Excel and take your work-from-home job prospects to the next level? Jump-start your career with our Premium A-to-Z Microsoft Excel Training Bundle from the new Gadget Hacks Shop and get lifetime access to more than 40 hours of Basic to Advanced instruction on functions, formula, tools, and more.