Here's another version of the Nyingma seal. You will notice the syllable in the center is "AH" not "OM," and the two-headed "lotsawa" birds are apparently of the same family (rather than two different families).
Copyright (c) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 by Tulku Urgyan Tenpa Rinpoche, a corporation. All rights reserved. Individually copyrighted text and graphics herein are copyright the respective copyright holders. TRIGGER WARNING: The beliefs and opinions expressed herein may act as a trigger for your anxiety, PTSD, and/or feelings of guilt and self-loathing, If you suffer from these conditions, or if you entertain irrational beliefs that posts to this blog are written "just for you," please take stock of your obsessions before reading further.