Southwest Airlines held its annual shareholders meeting in Denver on Wednesday, and there was an elephant the size of a 737 inside the conference room and a labor protest on the street outside. Southwest, the Dallas-based low-cost carrier with the striking blue, red and yellow planes, was hit hard by the worldwide grounding of Boeing’s 737 Max jets this spring following fatal crashes in Ethiopia and Indonesia. The airline flies exclusively on 737s, including 34 Max aircraft, which is about 5 percent of its active fleet of 753 planes, CEO and board chairman Gary Kelly said Wednesday.