Orchids roots do not always grow inside the pot - in fact they are often aerial, but they rarely stick themselves to the outside of the pot. I guess the clay pot keeps some humidity, and that's why they are there.
@ninaganci Thanks! They are planted on volcanic gravel, not soil, I just water them once or twice a week - and add a little orchid food when I remember, which is not often.
Those roots look so healthy. I got an orchid for Valentine's Day among other flowers. Just got reminded by you to water them and add a little food. thanks so much, Monica.