I have a similar fork on a Giant Revive, and it didn't work with the particular torque arms I tried, due to the disk brake tab behind the fork - which is bigger than your fender eyelet. I didn't try this type though - it very well might work...

http://www.ebikes.ca/store/photos/TorqArmRev3.jpg

I think the piece on the dropout would drop down enough to clear the bottom, and then the main arm could be on
either the inside or outside to see which way it could bolt to the fender islet, along with a pipe clamp above the eyelet...That looks like a Bafang on there, which isn't a huge motor, although it is geared so could produce fair torqe - you could be all right without an arm - I like the feeling of security though.

Chris