See Increased Screen Real Estate for Other Configuration Settings in Property Editors
Where: This change applies to Lightning Experience and Salesforce Classic in Essentials, Professional, Enterprise, Performance, Unlimited, and Developer editions.
Why: When you first drag a new element onto the canvas, the Label, API Name, and Description fields remain unchanged and are easily seen and editable. But when you edit an existing element, the amount of space that these fields take up is minimized. The API name appears in parentheses. The Description field doesn’t appear unless it contains a value. If the description is longer than three lines, then we truncate it to three lines and follow it with an ellipsis (...). Click the pencil icon () to edit the label, API name, and description values.
After you click the pencil icon, the fields don’t collapse again in edit mode until you close and reopen the element for editing.