Indus Valley Civilization script is the biggest mystery of Ancient India History. Many scholars have tried to decipher the script but have been unable to come on a consensus.
The information on Indus valley civilization becomes limited due to its ambiguous script and historians have not been able to find a Rosetta stone till date so that a proper decipherment could be done.
The picture has something written on it but can't be deciphered and in it, it seems like a man is worshipping a deity of peeple tree, there is a goat nearby (probably for sacrifice) and there are seven attendants who can be considered sapt Matrikas. In another seal as well there is one goddess attended by seven goddesses and each Goddess has its own animal (probably their vahans or the animals were sacrificed to them).
The above seal shows a person (looks like a female) slaying a bull and a deity sitting in yogic posture. Either it's a scene of sacrifice to the deity or its depiction of Mahishasura Mardini.
So, the inability decipherment of Indus valley civilization seals is a huge block in understanding the core of the Civilization. But it's absolutely clear that Yoga was a huge part of Indus Valley Culture.