Two hundred kilobytes is generous for a photo. It covers the NEET and JEE photo range, looks sharp at 1400 px on any screen, and is small enough to send in bulk over WhatsApp as documents. The tool lands the quality just under the cap so you keep the maximum detail the limit allows.
At 200 KB you can expect about 1300 to 1500 px on the long side. The exact number depends on how much fine detail the image has: skies and plain walls compress well, foliage and fabric don't.
Tip: If the result is already under 200 KB at full resolution, the tool leaves the pixels untouched and only re-encodes.