Yes, the picture is crap. But if you look at the cylinder and hose, neither are set up as flare fittings to seal on their own. The washer is required, as I found out the hard way on my first 240Z during the transmission conversion from automatic to 4 speed.

If your old setup did not have the washer, it was not stock, or even OE-style.

Well it was a nabco and 11/16th, but maybe your right, I will go take a closer look. However, I will say this.

When I installed the 72 slave on my car with this hose, and bled it, it did not leak at all. Not even a drop sans copper washer.

Maybe the stack up is just better on the nabco's. OR maybe it would have started to leak later. But for the week it was installed, it did not leak. The Beck/Arnley leaked from the get go with just gravity. I can say that I do not think the hose I had was original. So may be hose was replaced a long time ago, and with it the copper washer was lost as well.

Thanks very much for posting that image Arne.

UPDATE: I took Arne's advice and used a copper crush washer on the Beck/Arnley slave and it did not leak at all, and in fact worked. I am still unhappy with the angle of attack on the clutch fork and will replace the B/A slave with the Nabco when it comes in, but I can drive the Z again!