Gazing intentionally at pictures (of living things) in order to derive pleasure is haraam. If the gaze falls on such pictures unintentionally, it will not be sinful.
Someone asked: “What if the picture is viewed from an artistic point of view?”
Hadhrat Thanvi rahimahullāh replied: “Forget about artistic achievement or the value of the artist. It is unlawful to look at some things created by even the True Artist – Allah Ta’ala. Gazing at women and young lads is haraam. The Fuqaha have well understood the dangers of ‘ostensibly’ viewing pictures for the sake of artistic appreciation. The Fuqaha have ruled that it is not even permissible to look at wine in order to derive mental pleasure.”