No. Most of the time the small images (64x64 in that video) are deliberately created by downscaling images with the same resolution as the upscale target (here

No. Most of the time the small images (64x64 in that video) are deliberately created by downscaling images with the same resolution as the upscale target (here 1024x1024). The source is usually called a reference image. This allows comparing the results of the algorithm with the ground truth (what the person or object actually looked like). What you're looking at is what the OP meant by input images.