Pixels and kilobytes, worked as separate limits
A numeric look at a portrait that is both too wide and too heavy.
Start with a source of 1800×2400 pixels, about 2 MB as a high-quality JPEG. The form wants at most 413×531 pixels and at most 200 KB. Those are two constraints.
The aspect 1800/2400 is 0.75. The target 413/531 is about 0.778 (35:45). A center crop to 3:4, then a scale that fits inside 413×531, lands on 413×531 if you crop to that ratio first. Scaling without a crop would letterbox or squash. This tool crops, then scales. It does not stretch.
The kilobyte result is not a fixed number. The same dimensions encode smaller when the picture is smooth. The resizer binary-searches JPEG quality and, if the floor is still too heavy, scales down again. The pass/fail row shows the bytes of the file you are about to download.
Open Resize and use the sample photo to see a before and after. The static example with assumptions is on Worked example: a photo sized for a 200 KB portrait.