Your example is a conditional statement, so in this instance, the opening "when" has a similar meaning to "if". It means that if you consider something in a particular way, you reach a certain conclusion.
If these proposals are considered out of context both interpretations are tenable.
The reason "when" is sometimes used as opposed to "if" is that "if" may be entirely hypothetical, whereas "when" implies that you may well meet the conditions of the statement. You may also come across the idiom "if and when" preceding a conditional statement like this.
If you were a mother you would understand.
This does not imply that the person being spoken to will ever become a mother. You could even say this to a man.
When you become a mother you will understand.
This implies that the person being spoken to will one day be a mother.