What does this transaction mean?
The owner of 1E9b2CvbB9pKT617zNbxoVNH65XqMjarPX is likely the same person as the owner of 1JXstXTaeg6eH3wCXvdC7TYSA8ntWAsPc8. A single user can have as many addresses as they want. When the sender wished to send .0001 BTC to 121orLQW2LanEtso2htwZSfZ3vV4toLKt6, two of their addresses were emptied to meet the required amount. 

The inputs sum up to .00020782, but only .0001 is sent to 121orLQW2LanEtso2htwZSfZ3vV4toLKt6. The remaining .00010782 was used as a miner's fee, and went to the miner who mined the block this transaction is included in.