A novel abstract non-humanoid soft robot with four pneumatically actuated chambers was developed with the aim to signal specific emotions by altering its shape, movements, and breathing rates. Through a user study we investigated how observers perceived the robot's emotional state at different breathing rates. An online questionnaire utilizing the Self-Assessment Manikin scale was used to evaluate pleasure, arousal, and dominance. Our findings show that a slow breathing rate between 7-12.5 breaths per minute corresponds to a high level of pleasure, whereas a high breathing rate of 40 breaths per minute corresponds to a high level of arousal. Participants' gender, in addition, influences the perception of pleasure and arousal at different breathing rates. The findings demonstrate the possibility of signalling emotions through breathing patterns with a non-humanoid soft robot.