What does Isaiah 58:5 mean?

Do you think this is the kind of fast I want—a day for people to go hungry, bow their heads like reeds, and dress in sackcloth and ashes? Is that what you call a fast, a day that pleases the Lord? Isaiah 58:5 - Modern Text Bible

(God questions whether outward displays of sorrow are what He really wants. He’s looking for something deeper.)