Showing the absence (unavailability) of a widespread and expected feature is clearer to the users, as extra legroom is a standard among airlines.

It's also clearer that the app is working as expected. If extra legroom legend is not shown, it prompts some possible questions from the user:

• Is the app working correctly, did something not load?
• Does this airline not offer extra legroom?
• Is it me? I can't find any extra legroom seats?

Better off to show the legend; it's clearer, and doesn't waste the users time scanning the page to find what's unavailable. You can also test the language to see what's clearest ('no seats', etc.).

Showing the absence (unavailability) of a widespread and expected feature is clearer to the users, as extra legroom is a standard among airlines.

It's also clearer that the app is working as expected. If the extra legroom legend is not shown, it prompts some possible questions from the user:

• Is the app working correctly, did something not load?
• Does this airline not offer extra legroom?
• Is it me? I can't find any extra legroom seats...

Better off to show the legend; it's clearer, and doesn't waste the users time scanning the page to find what's unavailable. You can also test the language to see what's clearest ('no seats', etc.).

Showing the absence (unavailability) of a widespread and expected feature is clearer to the users, as extra legroom is a standard among airlines.

It's also clearer that the app is working as expected. If extra legroom is not shown, it prompts some possible questions from the user:

• Is the app working correctly, did something not load?
• Does this airline not offer extra legroom?
• Is it me? I can't find any extra legroom seats?

Better off to show it; it's clearer, and doesn't waste the users time scanning the page to find what's unavailable.

Showing the absence (unavailability) of a widespread and expected feature is clearer to the users, as extra legroom is a standard among airlines.

It's also clearer that the app is working as expected. If extra legroom legend is not shown, it prompts some possible questions from the user:

• Is the app working correctly, did something not load?
• Does this airline not offer extra legroom?
• Is it me? I can't find any extra legroom seats?

Better off to show the legend; it's clearer, and doesn't waste the users time scanning the page to find what's unavailable. You can also test the language to see what's clearest ('no seats', etc.).