The speaker directly addresses the tiger, imagining its bright flashes of color in the middle night of forests, so these lines of tiger are very conspicuous and can be seen even in the darkness of forest, this is a metaphor so the poet compares how the lines of tiger skin look exactly the same as the lines of fire, then he asks which an immortal being could possibly have created you ?the poet describes the creator id daring to create such a terrifying creature then he asks which kind of wings do you have, it,s a reference to Icarus from greek mythology Icarus wanted to fly with wings of wax but the sun burned his wings, so the poet asks the creator which wings you have to aspire creating this fearful creature, here the tiger is compared with the sun of Icarus and the creator represent Icarus, also he asks which kind of hand u have to touch this fiery creature without getting hurt!This a rhetorical question to show the admiration of god, creation and the strength of god and his power which is symbolize to Jesus Christ
The speaker wonders in which depths and skies the tiger,s fiery eyes were made?