/dev/sda5 is mounted at / and it's my filesystem

piotr@thinkpad:~$ sudo mkdir /home/mpoint
piotr@thinkpad:~$ sudo mount /dev/sda5 /home/mpoint

so now I can do:

piotr@thinkpad:~$ cd /home/mpoint/home/mpoint

and when I'm in second mpoint directory, it's empty.

My questions are:

1. Frome a title

2. Why this second mpoint dir is empty?

/dev/sda5 is mounted at / and it's my filesystem

piotr@thinkpad:~$ sudo mkdir /home/mpoint
piotr@thinkpad:~$ sudo mount /dev/sda5 /home/mpoint

so now I can do:

piotr@thinkpad:~$ cd /home/mpoint/home/mpoint

and when I'm in second mpoint directory, it's empty.

My questions are:

1. Why is it possible to "loop" a filesystem by mounting it to one of its folders?

2. Why this second mpoint dir is empty?