Only images that are not in use by the device can be released.
Releasing images is a read-only operation that will not affect the content of the released images. Upon reacquiring the image, the image contents and its layout will be the same as they were prior to releasing it. However, if a mechanism other than Vulkan is used to modify the platform window associated with the swapchain, the content of all presentable images in the swapchain becomes undefined.
This functionality is useful during swapchain recreation, where acquired images from the old swapchain can be released instead of presented.
For more information, see the Vulkan Specification
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.