Any idea why Android Studio sometimes shows different icons for `.kt` files

Little question here, but any idea why sometimes Android Studio will render different icons for what seem like normal Kotlin files?

In this specific screenshot, why is Question.kt not rendered in the source list with the .kt extension. Why does it have a different icon?

When the file contains only a single class/interface/etc declaration that matches the name of the file, then it displays the file by its type.

For example, the following Question.kt file would display the class icon and name Question

package com.bignerdranch.android.geoquiz

data class Question(@StringRes val textResId: Int, val answer: Boolean)

But the following will display the Kotlin icon and the name Question.kt

package com.bignerdranch.android.geoquiz

private const val DEFAULT_ANSWER = false

data class Question(@StringRes val textRedId: Int, val answer: Boolean = DEFAULT_ANSWER)

because this latter example has two declarations:

  1. DEFAULT_ANSWER

  2. Question