does it have good/new pads in it ???
very worn pads will not work well if at all
is the pedal pushing the master rod exactly straight into the master ???
if not, it will not push up into the master far enuf to do anything, it must be perfectly aligned
(it looks alinged good)
remove the rezzie lid and keep full of fluid at all times,
pull the caliper off the carrier, flip it so the bleeders are facing upwards, and hold it higher than the master, so any air will travel up and out easier.
pump pedal a few times and hold it down, the open and close the bleeder, only release the pedal after bleeder is closed
i like to do the bleeder near the line first, till no air comes out, just straight fluid
repeat for opposite side
report results, or PM me for further assistance