Revenue=/=profit. After you take out all their expenses they made 16.8 billion.
Wikinvest.com is telling me that Walmart's 2015 profits were $130.6 billion.
I didn't bring it up before, but the math on that image is incorrect. Many of Walmart's employees make more than $15/hr, meaning that Walmart won't have to pay them any extra money. Also, the average employee salary on that image is out of date. Right now the average sales associate makes $8.81/hr (IBISWorld).
Let me demonstrate why the math on that image is a completely incorrect way to calculate payroll increases. Let's imagine (hypothetically) that 1,750,000 people work at Walmart for $7.25/hr, and 250,000 work for $35/hr. If we average the wages, we get $10.72/hr. So then, the calculated 'pay increase' using the method on the image is (15 - 10.72)*2,000,000 or $8,560,000/hr. However, in reality, the actual payroll increase is $13,562,500/hr. Hugely different numbers.
You might notice that the second number is bigger, and that's because the accuracy of the estimate depends on the proportions of how many people make certain wages at Walmart. Considering the fact that there's hundreds of thousands of pharmacists, managers, and corporate employees that work for Walmart for more than $30,000/yr, then the math on that image is probably completely out of the ballpark. Back-of-the-envelope math and political facebook memes shouldn't take precedence over actual research.