Galaxy Tab S4: How to Use Smart Select

Touch Air Command → Touch Smart select → Touch CONFIRM → Touch type shape (For this example, touch Rectangle) → Touch & Hold location on the screen → Drag the rectangle → Touch Save

Pictorial representation of the above settings are as follows :

Note:

Auto select: Allow Smart select to automatically select content to extract.

Extract text: Identify and extract text from the selected content. 

Pin to screen: Pin the selected image to Home screen.

Bixby Vision: Use Bixby Vision on the selected image.

Draw: Draw on the captured screen using the S Pen.

Share: Choose a sharing method to share your content.

Save: Save the content to the Gallery app.