They filmed this scene late in post production but cut it because it didn't make sense for Shaak Ti to be meditating while the Temple is being destroyed. I suppose Lucas liked the design of Shaak Ti and wanted an on screen death for the character after he cut her original death at the hands of Grievous in the opening of the film.
The second part of the video where he is walking through the hall as the Clones shoot down Jedi could have been cool to see when finished though.
In fact most of the Jedi Temple massacre was scheduled for filming in post production. This was a mistake as it put the entire sequence on the back burner and meant blue screen deaths for most and put scenes in a state of fluctuation without it being locked and finished early enough for John Williams to write new music for it.