Desktop vs. extension

What are the differences between Stacking on the Desktop Wallet and stacking in the browser?
Leather for Desktop has the same functionality before and after the launch of Stacks 2.1 and POX2.
Whereas the Stacking Dapp, that can be used in conjunction with the Wallet extension will get the options to take advantages of the features added in Proof of Transfer 2 (PoX2). Namely: topping off when stacking on your own stackIncrease, and extending the duration stackExtend (without the need for a cooldown cycle as was the case in PoX1).
When pooling there are similar improvements for the pool operator so that they can extend the duration without requiring cooldown cycles. When stacking in a pool you will not see these changes, they remain in the background with the pool operators (i.e. Friedger, Planbetter and Xverse) handling the relevant contract calls for you.