When the Lord brought back the captives to Zion,
we were like men who dreamed.
Our mouths were filled with laughter,
our tongues with songs of joy.

Psalm 126 is about gratitude and joy of the redeemed. In verses 5-6 the magnitude of this joy is shown by wildly swinging contrasts:

Those who sow in tears
will reap with songs of joy.
He who goes out weeping,
carrying seed to sow,
will return with songs of joy,
carrying sheaves with him.

A similar scene of contrast happens at Simon’s home when a sinful woman bursts in to anoint Jesus’ feet with tears and perfume (Luke 7:36-50).

I find my own joy and love for Jesus pretty puny, similar to Simon’s. There isn’t much contrast making my picture lifeless and ordinary. So I return to Psalm 126 to meditate upon what God has done for me and I begin to sing the song of joy.

The photograph of tree trunks is joyous because of the contrast. It is the same with life.