Reading from the Vimuttimagga, the class keeps attention on the bare point where the breath touches the nostril, never forcing it longer or shorter. The "sign" that ripens there is usually mistranslated as an image; it is really a touch, like spun silk or a soft breeze. The instruction is to stay with that and let it open into absorption, ignoring the other signs that arise.
In this teaching, Lama Mark Webber is giving instruction on the practice of Anapanasati. The teachings were given in 2011 in Switzerland.