Carnival (CCL) shares are up more than 40% over the last year, but have pulled back from recent highs. Despite this, the company's record earnings and strong forward-looking booking mentions are positives. However, Likefolio's Megan Brantley notes that CCL's high debt-to-equity ratio and exposure to budget-conscious consumers could be headwinds. Additionally, changes to its loyalty program have sparked a consumer backlash, which could impact sentiment and demand. With the job market showing signs of potential weakness, Brantley says CCL's stock may be more vulnerable to a slowdown than its peers, such as Royal Caribbean (RCL) and Norwegian (NCLH).