It simply states that ADAM was created as ADAM was,that is 60 ft,while the rest of Bani Adam are created by the method of procreation,meaning a man and a woman will meet,the wman will conceive and then the process of birth,childhood,adulthood etc,WHILE ADAM WAS CREATED AS HE WAS,in ADAM,S OWN IMAGE,he did not have to pass through the process of conception and birth etc. It is a misconception to think that Adam was created in ALLAH,S image,as is popularly thought. It also answars your question of mention of lenghth here,because in both the places the word HE means ADAM and not ALLAH Subhanahu was taala.