Recall that turning around in shine will leave you unable to jump out for a few frames.
Running shine leaves you with enough momentum that some jump cancelled actions can actually hit a sliding opponent. Grab is one of them, and the execution is basically a combination of running shine and Shine grab.
Due to shine's mechanics, this option soundly beats defensive counterplay like run-up shield or ASDI down. However, it does not work against characters that get knocked down by shine.