Originally Posted by kalutika
Blowing a heart shaped vortex is a physical impossibility. If there is a slight downward gust that pushed the circle into a heart shape it could appear as such but will disrupt the vortex and ruin it's stability. Without an outside force acting upon the circle of smoke it can never be anything else. There is no way to blow from only one part of you mouth. There is no way for a vortex to be made in a shape other than a circle. A smoke heart cannot be done. Sorry those of you that claim to have done it but that was just a result of airflow in the room and an unstable vortex that was collapsing in a way you recognized as a heart.
I don't think anyone is claiming they blew a smoke heart, i'm fairly certain they're saying they modified pre-formed smoke rings that have already been expelled by their food receptors into that of a heart shape. This is somewhat similar to the aforementioned environmental anomalies that you say caused the shape, only user-controlled.