I like having more than one airliner in one shot as you have probably figured by now if you read the blog a lot. Since SFO has parallel approaches, getting this type of shot is not a rarity although you do appreciate it when it works out. In this case a Skywest Embraer E175 (operating for United Express) and a Southwest 737 were lined up on the approach. They were offset a bit so their relative position from my viewpoint changed during the approach which provided a nice variety of compositions.