Want to get into polymarket but having a fundamental problem understanding their contracts & docs

in both addFunding and removeFunding, why am i receiving conditional tokens in BOTH functions?
` conditionalTokens.safeBatchTransferFrom`

https://github [dot com] /gnosis/conditional-tokens-market-makers/blob/master/contracts/FixedProductMarketMaker.sol

their docs are minimalistic
docs.polymarket [dot com] /#add-liquidity