What's the significance of the 2 periods here "../bin/python"

What's the significance of the 2 periods here "../bin/python"

I'm trying to do the quick installation described here:
https://github.com/plumi/plumi.app/blob/master/docs/INSTALL.rst
One of the instructions is to run
"~/plumi.app/ffmpeg$../bin/python bootstrap.py && ./bin/buildout -vN"
There are 2 periods before the first /bin and there's one period before
the second /bin
I'm wondering if this is a typo, because a little before that, there's an
instruction as follows:
"~/plumi.app$./bin/python bootstrap.py && ./bin/buildout -v"
And in this case, there's only one period before each /bin
Also, I understand that ./bin/python is the same thing as bin/python but
does Ubuntu Linux Server correctly interpret ./bin/python ??
Thanks.