"The depth and passion of its earnest glance" - Robert BrowningWatch
Full paragraph thing: (thank you in advance)
Frà Pandolf" by design, for never read
Strangers like you that pictured countenance,
The depth and passion of its earnest glance,
But to myself they turned (since none puts by
The curtain I have drawn for you, but I)
And seemed as they would ask me, if they durst,
How such a glance came there; so, not the first
Are you to turn and ask thus.
Although not spoken within the poem, the Emmisary has asked the Duke why the Duchess is looking as she does - in the portrait.
The image of the Duchess is so extraordinary that - as the Duke comments - the Emmisary is not the first to comment on the Duchess' expression.
It appears that this portrait has captured the full passion of the Duchess - just as she was when she was alive. Ironically it is this same passion that led to her death. Ironically later in the poem the Duke informs the Emmisary that he considers this portrait a wonder now. The irony is that this same passion is what led to the Duchess being killed.
As a picture the Duke treasures this image of the Duchess. As a real live person it irritated so much that he ordered her execution.
He treasures this portrait that he has it curtained off. No one is allowed to see it unless he gives permission.
Hope that helps.