When Buddhism got to China, the bare-shoulder style of the original monks' robes became a problem. In Chinese culture it was improper not to keep the arms and shoulders covered in public. So, Chinese Buddhist monks began to wear sleeved robes similar to a Taoist scholar's robe of the early 1st millennium CE.
Because Chinese Buddhist monks lived in self-sufficient monastic communities, monks spent part of each day doing custodial and gardening chores. Wearing the kashaya all the time was not practical, so it came to be saved for formal occasions. The robe in the photograph is an "everyday" robe for non-ceremonial wear.
