The first paragraph of the Hyperledger Burrow documentation contains a good description of what this framework is. This description is as follows:
"Hyperledger Burrow is a permissioned Ethereum smart-contract blockchain node. It executes Ethereum EVM smart contract code (usually written in Solidity) on a permissioned virtual machine. Burrow provides transaction finality and high transaction throughput on a proof-of-stake Tendermint consensus engine."
The idea is indeed to work with Ethereum smart contracts. The high level of architecture applied to Hyperledger Burrow can be seen in the following diagram: