The question asks for the changes observed by the gopis in Krishna that led them to want to take their hearts back. The context highlights that gopis taunted Uddhav by saying Krishna has now learned politics ('हरि अब राजनीति पढ़ आए हैं'), indicating a shift from pure love to diplomacy. Additionally, instead of returning, Krishna sent a dry message of yoga and knowledge through Uddhav, showing he moved from the path of love to the path of knowledge. Furthermore, he forgot his 'marjaada' (duties towards gopis) and 'rajdharma' (welfare of subjects). These changes form the basis of the gopis' disappointment.