The left one is disabled, but not visibly so. In one of the designs, there’s a new suggestion for this:
That is: a single “split pill” visual appearance, with the enabled button a charcoal chevron, and the disabled button “Light gray”. It’s much clearer here that one button is enabled and the other is not. They are also both square.
The buttons for scrolling look like this:
The left one is disabled, but not visibly so. In one of the designs, there’s a new suggestion for this:
That is: a single “split pill” visual appearance, with the enabled button a charcoal chevron, and the disabled button “Light gray”. It’s much clearer here that one button is enabled and the other is not. They are also both square.