Jesus Smiles and Preacher Eyebrows
A Jesus Smile is that particular weird strained, artificially-happy smile worn by the very most toxic of Christians. While a pedosmile is a creeptastic smile associated with pedophiles who are thought to typically display them around children, a Jesus Smile is put on all the time in any context where the Christian wants to look as Jesus-filled as possible--and as credible, harmless, and joyful as possible. These are all traits that Christians think improve their chances of scoring a sale as well as increase their own standing in Christian culture.
When someone who's happy smiles, their faces do predictable--and often involuntary--things. An insincere smile only involves those facial muscles that people can actually control, while a sincere one uses all the muscles--even the uncontrollable ones.
A Duchenne smile is the sincere one. A non-sincere smile is often called a Pan Am smile (or a Botox smile) after the requirement for Pan American stewardess to smile all the time, even when they don't want to smile. Much the same requirement is laid upon Christians, particularly in the far-right variants. On the blog, I've talked before about the Duggar women's extremely forced-looking smiles.
People can tell the difference between a non-sincere smile and a sincere one--and the dissembling attempt to smile when good cheer is not actually felt can creep us out or even anger a lot of folks. (Though some people are happy to see even fake smiles!)
Kirk Cameron is the prototypical wearer of the Jesus Smile (note that he's been at it for so long that he's managed to give himself the weirdest crow's feet wrinkles on the planet):
Often we also talk about preacher eyebrows as well. Preacher eyebrows are the weirdly scrunched-up raised eyebrows worn by Christians who wish to appear super-sincere. For extra-dextra sincerity, preacher eyebrows are paired with abnormally-widened eyes and a slightly tilted-backward head.
Ted Cruz tends to wear both of these features, especially when he's campaigning. A neurologist notes that these features make the politician appear far less sincere to most observers. As that writeup puts it so well, "Seeing someone convey negative emotions (especially when they're trying not to) makes us subconsciously want to back away."