Although not often pictured for purposes of Jewish worship in these days, in older times they were displayed.
You just happen to live in an age where the main thrust of Judaism is to discount the use of images.
Maimonides says (Guide for the Perplexed III:45) that the figures of the cherubayim/Seraphin were placed in the sanctuary only to preserve among the people the belief in angels, there being two in order that the people might not be led to believe that they were the image of God.