This examples allows you to lock tokens on one chain, then redeem them on another chain as tokens.
Any tokens on the other chain can be burned, then the original value withdrawn on the original chain.
This allows you to, for example, deposit Ether on Ropsten, then on Kovan use the tokenized Ropsten-Ether, transfer it to people or whatever... then whoever holds the tokens can burn them and withdraw the original Ropsten Ether back on Ropsten.
This examples allows you to lock tokens on one chain, then redeem them on another chain as tokens.
Any tokens on the other chain can be burned, then the original value withdrawn on the original chain.
This allows you to, for example, deposit Ether on Ropsten, then on Kovan use the tokenized Ropsten-Ether, transfer it to people or whatever... then whoever holds the tokens can burn them and withdraw the original Ropsten Ether back on Ropsten.