If we assume portals obey https://en.wikipedia.org/wiki/Galilean_invariance, then there’s no difference between “the tram|portal is moving and the people are stationary” and “the tram|portal is stationary and the people are moving.” The outcome should be the same.
If we assume portals obey https://en.wikipedia.org/wiki/Galilean_invariance, then there’s no difference between “the tram|portal is moving and the people are stationary” and “the tram|portal is stationary and the people are moving.” The outcome should be the same.