How to compare harness fit
Measure against the right part of the garment.
Waist and leg range
Compare the waist and leg measurements separately. A harness with buckles or sliders can list a different fit range for each strap. A garment-style option may use a size chart instead.
What the photos can show
Photos can show the locations of adjusters and clips. Use a published chart for actual fit limits and confirm the chart applies to your selected variant.