I'd like to see a 5x reduction in those limits but awesome idea.
Modern camera's take pictures measured in megabytes, and you're suggesting the per image max be 200kb, and total images to be 400kb?! Two crappy quality images would blow that out of the water (Heck a single crappy image could).
I get that this is a prototype, and seems to be intended for mobile devices, etc. But those limits are already something you'd have to work for, I'd argue it's near impossible at 5x less resources.
tl;dr by todays standards a 5x reduction in those limits is just code golf.
The per-image limit is currently set at 1MiB (not 200KiB).
Hope that helps.