Hi Roman,
what we see here, is a Class B (multisig) Mastercoin transaction (
https://masterchest.info/files/mscappendix_draft.pdf)
https://masterchain.info/simplesend.html?tx=f4ff244d1595b340e5634dde6b077ee99e6657c411e1f6701a9967e5bc850a57¤cy=MSCLet's say some Bitcoin address already has MSC or TMSC and wants to send some of them to another Bitcoin address. He does that by encoding a Mastercoin transaction into the Bitcoin blockchain. The way to encode it, is to generate a very small Bitcoin transaction with some data Mastercoin data embedded, which says: "move n amount to MSC/TMSC from source to destination". Bitcoin network simply sees this as some bitcoins moving, it doesn't notice the embedded data.
Mastercoin parsers however look for these special transactions on the blockchain. An easy way to identify them, is to watch for bitcoins moving to the Exodus address (you can see it as one of the outputs: 1EXoDusjGwvnjZUyKkxZ4UHEf77z6A5S4P). Once a parser sees the transaction, it checks if it really fits the Mastercoin specification and marks MSC/TMSC as transfered. Everyone can write a parser and trace the transactions.
So what happened here is that the source has generated a transaction with several outputs:
17rExRiMaJGgHPVuYjHL21mEhfzbRPRkui -->
--> 1CKPYQPiVKMBEHqWco9sNNLNeTCjGSxfrn (MSC receiver)
--> 1EXoDusjGwvnjZUyKkxZ4UHEf77z6A5S4P (a marker for a parser to identify a Mastercoin transaction)
--> 16FcCqZk5XF4sDkcFGQ5twbt7S3E8GdsHh (encoded control data: how many MSC has been sent, type of transaction, is it MSC or TMSC, etc. It's not a "real" Bitcoin address!)
--> 17rExRiMaJGgHPVuYjHL21mEhfzbRPRkui (change received back to source)
The amount of bitcoins transfered is pretty much irrelevant, as long as it fits the Mastercoin spec.
There's small problem with this situation is that we use a "fake" Bitcoin address to store the transaction data. This means it receives some bitcoins that cannot be spent (there's no private key for data address), and this dust will have to be forever stored in blockchain. Here we see a Class B transaction, which avoids that by creating a multisig transaction type, in which bitcoin dust can be redeemed by sender. Either Class A or Class B transactions are valid, just Class B is a bit more complicated (and cleaner).
What boils down to: to transfer mastercoins you have to create a special Bitcoin transaction with "fake" addresses and encode tx data on it. The tx is then frozen in the Bitcoin blockchain, and a Mastercoin parser can always trace the path of mastercoins by looking for a marker, which is the Exodus address.
I hope this clears a bit. If you wish more details you can find them in specifications, or you can ask again