Let's look at that.
If there was no load on the other phase, then the voltage on your phase would fall to zero. If there was a tiny load on the other phase, the voltage would be slight. If there was a huge load on the other phase, your phase would go high in voltage.

It's how a voltage divider works: you have a voltage from one phase to the other, and the larger resistance ( = lower load) gets the lion's share of the voltage.