The Indus Valley Civilization that had its peak from about 2600 till 1900 BC is still shrouded in mystery. That the script is still undeciphered doesn't help here.
The top right image depicts one of the most controversial finds. Many claim it depicts a horned god in yoga posture with three faces - similar to images and sculptures we find in mature Hinduism. If so, this might mean that some form of meditiation might already be part of this ancient culture (c. 4000 years old!!!)
Lets's go through the facts. Show this picture to almost anyone and they will recognize the meditative posture, but is it? Seals from Denmark show a horned being in a similar posture and here nobody things of yoga. What about the three heads? Zooming into the picture, a case can be made that the shape of the nose and lips are repeated on the sides of the head. However, people don't usually recognize this until they are pointed to it.
Of course, on image is not enough to make strong claims about the Indus culture, but we can have opinions. I'm always hopeful that this interpretation pans out. What is you opinion? Love to hear from you in the comments.