The thought of holding a fixed grin as the camera performed its magical duties was too much to contemplate, and so a non-committal blank stare became the norm.
想到在相机完成其神奇任务时必须保持固定的笑容，这让人难以想象，因此不置可否的空白眼神成了常态。
One explanation might be the loss of dignity displayed through a cheesy grin.
一个可能的解释是，露出傻笑会显得失去尊严。
A toothy grin (especially when there were gaps or blackened gnashers) lacked class: drunks, tramps, and music hall performers might gurn and grin with a smile as wide as Lewis Carroll's gum-exposing Cheshire Cat, but it was not a becoming look for properly bred persons.
露出牙齿的笑容（尤其是当有牙缝或发黑的牙齿时）显得缺乏教养：醉汉、流浪汉和音乐厅的表演者可能会像刘易斯·卡罗尔笔下露出牙龈的柴郡猫一样咧嘴大笑，但对真正有教养的人来说，这种笑容并不合适。
A toothy grin (especially when there were gaps or blackened gnashers) lacked class: drunks, tramps, and music hall performers might gurn and grin with a smile as wide as Lewis Carroll's gum-exposing Cheshire Cat, but it was not a becoming look for properly bred persons.
露出牙齿的笑容（尤其是当有牙缝或发黑的牙齿时）显得缺乏教养：醉汉、流浪汉和音乐厅的表演者可能会像刘易斯·卡罗尔笔下露出牙龈的柴郡猫一样咧嘴大笑，但对真正有教养的人来说，这种笑容并不合适。
例句取自历年考研英语真题，翻译为机器生成，仅供学习参考。