If you read between the lines and the screenshot shared, you will know that it was use to draw comparison between Steem Dollars (SBD) and convertible notes.

That is to say, just like convertible notes provide a way for investors to hold a debt that can later be converted into equity, SBD allows users to hold a currency that can later be converted into Steem or other assets within the Steemit ecosystem.

This mechanism is therefore designed to encourage participation in the community while providing a stable asset that can be used for transactions.

By allowing SBD to be convertible, it helps to enhance the network effect of the Steemit platform, with the hope of attracting more users and creating more value for those who hold the tokens.

Therefore, SBD itself does not earn you interest like a traditional savings account, instead it can be used to trade, invest, or convert into other currencies, including Steem or fiat currency.

When you hold SBD, you only get to benefit from price appreciation if the value of SBD increases over time. The idea of SBD being in the form of a loan comes from its mechanism of being a stablecoin, pegged to the value of one U.S. dollar. This means that while you hold SBD, you are essentially holding an asset that can be exchanged for a stable value, but it does not generate interest or rewards by simply holding it.