Boots: sole construction, shaft height and the half-size problem
Boot photos almost always frame the upper, because the upper is what sells. The outsole is where the money is. A cemented sole can be re-glued by a local cobbler; a stitch-down or welted construction is a different product at a different price. One photo of the sole edge and the stitching tells you which one you are being quoted.
Shaft height and calf fit are the second blind spot. Album rows list a size, not a circumference, and tall boots that fit the foot can still refuse to zip. Ask for the shaft height and the top opening measured flat, then compare with a pair you already own rather than with your shoe size.
Half sizes are rare and most Chinese lasts run short, so boots are the category where sizing up is most often the right call — especially if you plan to wear thick socks. Boots are also the most volumetric item in a typical order; check the volumetric weight before you assume a pair is cheap to ship.