I think I can explain it. Clevermining mines the current most profitable coin and automatically converts the rewards (of the mining) to BTC (Bitcoin). It has its own way to choose which coin is the most profitable, but you can check for example http://www.coinwarz.com/cryptocurrency to see which coin is the most profitable currently.
The homepage does indeed shows the LTC profitability. If for example you read "120% LTC Profitabilty", this means that you've earned 20% more BTC than you would earn if you would directly mine LTC and sell them for BTC. 100% LTC profitability means that you've earned the exact same amount of BTC as you would as you had mined LTC (and directly sold it for BTC).