I'm sorry but I am going to have to disagree on the chain length you are showing. It still looks too short ot me and the Park tool photo looks like a der ready to asplode when shifter under load (if it will shift)

You posted a picture earlier in the thread where the chain just touched the pulley in small/small. If you start from there and turn the B-Tension screw in until the chain no longer touches the pulley you will be good to go. This is regardless of what kind of chain you choose to use.