Yield optimizes will sell rewards on your behalf and then add them back to your original position. For example, you have LP tokens of x+y. Z is the reward token. The optimizer sells z as it accumulates and buys more of the x+y LP tokens and adds them to your position.
Penpie is a DeFi protocol that acts as an enhancement tool for Pendle Finance, which is a DeFi platform for earning yield on crypto.