If pictures were mountain ranges, contrast is the measure of whether they are the Catskills or the Rockies or the Himalayas. And if viewing a picture is a journey for the eyes, then traveling high contrast images is going to be exhausting! Make sure to bring a Sherpa and pack light. The eyes need variety ... but they also need rest. Mountains and plains. There are rewards as you round each corner and summit each peak but there is peace and rest in the valleys.
On the other side, low contrast images are more desert-like. Subtle variations of hue and color and light. Tone poems. Unless they get too dry. Then they are barren and thirsty places to visit and we can't wait to get back to the mountains again.
A classic reference book is, "Light - Science and Magic" by Hunter, Biver and Fuqua. My 2 cent summary is that lighting can be classified by its degree of contrast-iness (forgive me Mr. Webster). There's soft light and hard light. And where you place the light will affect the resulting contrast and apparent detail in that neighborhood.
For the image above, direct sunlight resulted in a contrasty feel.
Here is another one taken in soft shade. My frail attempts to improve contrast really failed here. The result is a little bit bland. It lacks punch or ... ummm ... pop ... or something. It may just be my white balance is off. Not sure. It wouldn't be the only thing about me that is just a little bit off ... ;D
More later ...
Blessings and peace,