make re-downloading the files when building LO for the second time.

Hey folks,
Its my first question here. Please pardon me if I am wrong somewhere.

I downloaded the source of LO, and built it from a fast internet
connection. Two days after building the source, my motherboard
crashed, and I got my laptop two days back.

So, today I did git pull, and got all the latest changes in the source. I ran
./install.sh
and then I ran
make

But then, many files were again getting downloaded in this build?

Isn't make is only responsible for recompiling only those parts which
were changed?

So why the download? I am a little tight on bandwidth?

Can somebody please tell me what point am I missing now?

-- 
Regards,
Anubhav Yadav
Imperial College of Engineering and Research,
Pune.