pronunciation - Why the masoretes wrote the tetragrammaton this way?

I am aware that there is already another question about the pronunciation if the tetragrammatron which is here:

What is the correct pronunciation of the Tetragrammaton?

But no one mentionned that the masoretes already wrote it this way:

יְהוָה

Is this the original pronunciation ? If not, then why the masoretes wrote it this way ?

Notice that there are no vowels (Tenu'ot) on the letters heh.