Minimal compression test: include a gradient and tiny text

A small Image Compressor sample should contain the difficult features of the real image: fine text, a gradient, sharp edges, or transparent pixels. Export it at the planned settings and compare with the source at 100% zoom and intended display size. Note output dimensions and byte size. A plain photograph might hide ringing that becomes obvious in a screenshot. Use harmless sample content so the test can be shared without exposing private data.