Themes
Re-creation, not reflection
The idea that most pleases the audience is that art should not merely hold 'the mirror up to nature', Hamlet's phrase for acting. Image's artist is a realist because he recognises an outside world of truth, and an idealist because he selects, abstracts and individualises. Wilde's summary sharpens the point: art is 're-creation more than a reflection, and not a repetition but rather a new song.' The artist, in this view, stands neither apart from nature nor merely copying its facts.
Impressive and expressive art
Wilde's one criticism is that Image did not make clear 'the contrast between impressive art and the art that is expressive also': between a purely pictorial subject, such as Whistler's fireworks or Van Huysum's roses, and one that carries 'historical associations or poetic memories.' The same distinction returns a year later in his notice of the bookbinding lecture, where he calls the handicrafts impressive rather than expressive arts.
The five-o'clock-tea critics
As in his notice of the first lecture, Wilde ends with the audience. Image's 'entire freedom from dogmatism and self-assertion' is held against him, and one young gentleman warns that 'virtuous modesty' may become 'a most vicious mannerism.' Wilde's last line, that 'sweet reasonableness' may not convert but 'always charms', is both a compliment to the lecturer and a joke at the expense of the fashionable crowd.