Explain why very large images need guard rails and how local processing should balance privacy with browser performance.
Very large images need size protection before compression
When someone drops in a very large image, canvas drawing and encoding can spike main-thread usage immediately.
A stable MVP should downscale oversized files first and clearly tell the user what happened.
Local processing still needs visible interaction feedback
People notice “the page froze” faster than they notice whether the task is local or server-side.
That is why status feedback, processing hints, previews, and download entry points need to be designed together.