Can somebody explain how this works on Poloniex

[BNO]

Hi folks,

i just tried out the margin trading on Poloniex and got really confused  
What i did: I moved some bitcoin form my exchange account to margin trading and started selling 10 ETH short. This was on sunday. When i sold the ETH short it said something about 2 day credit.

And this is the result in the trade logs   Can somebody explain me whats going on here please...

Why am i buying fractions of Ether when i want to short 10 ETH? Doese settlement mean the ether are bought back and sold again?

[Quickseller]

When you sell ETH (or any other altcoin, or even bitcoin) short, you need to first borrow the ETH (or whatever you are selling short) from someone who has a long position and is willing to lend to you. The lender will not be able to sell their position for as long as they have a loan outstanding to you. The loan is secured by the equity (the net value) in your account. When you are borrowing the ETH that you are selling short, you must compensate the lender for allowing you to borrow their ETH via the payment of interest. The "settlement" that shows up on your account is interest payments that you are paying to your lender. More specifically, you are taking out a new 10 ETH loan every two days to repay your previous ETH loan and the settlement amount is the interest paid to the first lender. When you "cover" your short position you will be able to repay your ETH lender and will no longer need to pay additional interest.

[BNO]

Hi,
i know how shorting works its just that the numbers there look a bit crazy and i don't get what it is and when fees are applied.
For example the first buy/settlement is 0.000000132 that is not enough for the interest and has no fees. The second one is 0.00597.... which could be interest and has fees...
And if it was true that position has to be bought back and given back to the person, than there should be a buy of 10 ETH which isn't.

So any help is really appreciated...