This very interesting poem is based around, as the title suggests, the poet receiving a picture of his mother who had recently died. Looking once again at the image of his mother allows him to process his grief, remembering happy times he shared with her whilst at the same time dealing with his feelings of loss and sadness.
The poem opens with the speaker wishing that the picture of his mother was real and that she could communicate with him. Even though the picture can't the "meek intelligence" of his mother's eyes comforts him nonetheless. He uses the power of "Fancy" to believe that the picture is actually his mother, which gives him an opportunity to talk to her and ask her questions, checking if she was aware of her son's grief when he heard that she had died. The speaker expresses his desire to meet his mother "on that peaceful shore" so that he will experience no grief again, though he does say that in time he learnt "submission" to his grief at having lost her.
The next section of the poem talks of the passing of time, and how their family house is now occupied by another family who do not know them. Even though this house was a "short lived possession," memory of her acts of kindness lasts a lot longer, and the poet remembers his mother's kindness and love as expressed when he was a child. The poet reflects that even if he had the chance to turn back time and have his mother with him again, he would probably not, saying:
...what here we call our life is such,
So little to be lov'd, and thou so much,
That I should ill requite thee to constrain
Thy unbound spirit into bonds again.
The last stanza reflects on the far better existence that his mother enjoys, and also comments on the way that this poem has allowed the speaker to re-live his childhood joys and to bid her farewell, thanks to the arrival of the picture. The rhyming couplet that ends the poem reflects on the way that death has not robbed him of his mother entirely:
Time has but half succeeded in his theft—
Thyself remov'd, thy power to sooth me left.
It may have taken away his mother from him, but it certainly has not taken away her power which is bequeathed to the poet.