Doesn't seem like there's anything special here? It's roughly what any novice would build if asked to diff two images in Go?
Which, sure, gets the job done faster than the single-thread `odiff` on a single image, but is quite irrelevant for a tool marketed for tests/CI where many images are likely to be compared in parallel already (and maybe a single core is even available).
Yep, uses as many goroutines as the number of CPUs, that's about it. Saying it's 3x faster or whatever in "benchmarks" without even saying what CPU is used in the benchmarks is just sketchy.