In it, the Rebbe lays out a new, super-powerful path in Avodas Hashem that has the power to bring us to remarkable shleimus in Torah, Avodah, and Gemilus Chasadim - or, in other words, in every aspect of our lives.
To "gaze at" the Third Beis HaMikdash and the final Geulah. In other words, not to simply think about them casually, but to visualize them and deeply connect mentally and emotionally to that vision.