I call geometry on head/seat tube angles, bb drop, wheelbase, cstays length, stack, reach... numbers that affect how the bike corners and how it deals w/ bumps, sudden acceleration: how the bike rides. A dropped top tube although visually striking mostly affects the ability to move your body around the bike. Brodie left the seat tube high showing where the top tube would be if placed parallel to ground: it would be the same "geometry". Another example is GT´s triple triangle: is it a different bike geometry? No; they just dropped the seatstays.