Several type designers and calligraphers are amazing creators of fonts, letters that become images in themselves. They design ambigrams, words or short phrases that can be read on horizontal, from left to right AND right to left. When they are mirrored horizontally, they either spell the same word or different ones.
A simple example is the word “mom” which, when flipped, reads “wow”.

I’m none of these master designers but as often, when I see something I like, I want to make one myself.
I make only 5 tees of each design.