little potatoes have big eyes
Young children can be very observant to the things they see, especially the screen on your phone or tablet. This is an updated modern analogy to the old saying “little pitchers have big ears” .
As I was looking over Grindr thumbnails, my young cousin looked over my shoulder and ask what I was doing. Fortunately it was just PG thumbnails. It made me very aware, and as my older cousin and I mentioned the “little pitchers have big ears” reference, we changed the reference to potatoes, because they have “eyes”. Little potatoes have big eyes. Now we are a pet of history.