sweetness
n
1 [U] quality of being sweet 甜; 芳香;悦耳; 新鲜; 可爱; 和蔼; 温柔.
2 (idm 习语) (all) ,sweetness and `light (ironic 反语) display of mildness and reason 温和而讲理
She's all sweetness and light provided you're doing what she wants. 只要顺著她, 她是又和蔼又讲理.
I suggest that we ask users of this machine what they think about it. We can photograph them using it too. Then we can put their comments at the top of the advertisement in big print. We can bring in some humour too. People enjoy reading humorous ads.