As other anons have pointed out, I’ve seen Pelosi ripping up other SOTU copies. It may just be her signal to her staff not to save or file a certain set of papers or it could be a normal not so quiet protest of what was contained within the text.
Usually Presidents use the SOTU to announce a wide range of policy goals, most of which are DOA as soon as they are spoken. Her ripping of the speech is likely her signal that Trump’s words are also DOA as far as she is concerned.