Dropdown with button Alt decision tree

The image

• contain text

  and

  • the text in the image is also present as real text nearby.
  • the text is only shown for visual effects.
  • the text in the image is not present otherwise.
• used in a link or a button, and would it be hard or impossible to understand what the link or the button does, if the image wasn’t there?
• contribute meaning to the current page or context?

  and

  • it’s a simple graphic or photograph.
  • it’s a graph or complex piece of information.
  • it shows content that is redundant to real text nearby.
• purely decorative or not intended for the user?
• use not listed above or it’s unclear what alt text to provide?