According to the Valiant marketing annual given to retailers at the Capital City Distributors conference explaining Valiant's upcoming releases and promotions, this is the first of two point of purchase posters supporting the UNITY crossover. It shipped with Valiant's March solicitations. The image is the same as the cover to UNITY #0 and is by legendary creator Barry Windsor-Smith.
The other poster is a Frank Miller UNITY poster that shipped with Valiant's April solicitations. That features the same art as the cover of Eternal Warrior #1.