what are the meaning of tensorborad log images during training flux-controlnet?

[dedoogong]

Hi, I'm trainining flux-controlnet with H100 gpus and I found tensorbrad Image tab shows the validation images.
the image of val images has 3 sub images like canny, and prompt and image as the log_validation function.

                validation_prompt = log["validation_prompt"]
                validation_image = log["validation_image"]

I wonder what is validation_prompt? some times validation_prompt look better than validation_image. what kind of image will be generated during inference after finished training? validation_prompt? or validation_image?

Please let me know any hint!