Translation:Your hair is really long!
Yes I have noticed that this happens throughout this course where a character has two or more different meanings and pronunciations. It seems to be pot luck whether you get the correct pronunciation or not, which is pretty unfortunate when you are trying to learn correct pronunciation as a beginner.
This is such a frequent and damaging shortcoming in the course that I am surprised it is allowed to happen. I guess the program that does the pronunciation doesn't know which is the correct meaning for the given context and the moderators are perhaps not given the ability to specify which pronunciation is correct (or they don't have the time to check every pronunciation).
长 has two independent meanings with the same character, a common phenomenon in Chinese called 多音字 （multiple readings). 'chang2' refers to long length of time or distance and consequently a 'consistent ability'. 'zhang3' is defined as either a person in the position of chief, headman, elder, even leader or the act of development and growing. The two words are visually identical in HanZi yet equally frequent, hence why the audio of the question has selected one at the detriment of the other, since the duolingo server stores 1 character for 1 sound regardless of context.