At the end of the episode, while escaping Slavers' Moon, Winn exits through the portal twice. He can be seen being pushed through the portal by Supergirl at the 32:08 mark. He is then seen standing by the portal again at the 32:24 mark and he goes through a few seconds later.
The other moons visible in Maaldoria's sky are all at different phases, even though they're nearby (else they'd look like stars); which means they should be lit by their sun Arcturus at very nearly the same angle.