thinker
n
(usu with an adj 通常与形容词连用) person who thinks deeply or in a specified way 深思的人; 用某方式思维的人; 思想家
a great, an original, an important, etc thinker 伟大的、 有创见的、 卓越的...思想家.
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.