Neither of us have a significant response to the basal social-mindset features of yawning contagion or vomiting contagion.
Despite their closeness to the autonomic brainstem response, these features are very difficult to trigger in ourselves, because they rarely appear alone. A person yawning will almost always be witnessed in association with other social-mindset features that have been associated with the innate survival mechanisms. The same goes for any display of a raw emotion such as smiling/laughing or frowning/crying.
Consequently, if there are sufficiently reduced survival-associated markers in the display (i.e. other social-mindset features), a person yawning can trigger a latent ‘itch’ in myself.
Mirror self-recognition
The clear exception to this list is mirror self-recognition.
Our own appearance and behaviours as seen in a mirror will always strongly resemble ourselves. They will always be in line with the weight our brains have given the innate survival centres over the social mindset and will always be in line with our own current behaviours, such as the clothes we wear, the actions we perform, etc. As such, they continue to trigger our latent social mindset.
It is the same reason we could empathise with someone who is significantly like us.