Gary Coyle’s winning portrait at the RHA Annual Exhibition is an accomplished work infused with ominous undertones, argues Donal Maguire

Portraiture, like other fine art genre, is difficult to define concisely. It is in constant fluctuation, subject to prevailing artistic concerns and the wider needs of society. However its endurance through history is tribute to both its perpetual relevance and to those artists who have felt compelled to explore or master the discipline