Animal welfare should be taken into account in the world of food. As people, we prefer to consume grass-fed beef, or free range chickens. It creates a better egg, or better meat. Even if not being consumed, we prefer to see these animals in healthy living conditions because we care. We do not want to see them injured, or kept in small confinement without enrichment or natural sustenance.

One animal in particular that is consumed, or kept as a pet, is the crab. 

Crabs in Global Foods are piled into tubs with no room to move, and no water to drink or swim in. Even though they are at a food market, the conditions they are in are inhumane. They are there without room to move, food to eat, or water to drink. Some of these crabs are also injured. 
Research has shown that, like other animals, they are happier and healthier receiving enrichment and proper care. They do have feeling in their shells. Research has also shown how cruel boiling them alive is, when there are better methods to eating crabs. I recommend looking into @howoethecrab on Instagram for learning more about how crabs live and function. 
As someone who cares about animals (though I am not vegan), seeing living conditions like this is sickening. Even if you just see them as food, would you at least want your food to be better taken care of? And have them be well fed? They deserve a better quality of life for as long as they have it. 
If these crabs are kept in better conditions, they will not only have a better and more humane  quality of life, but, for those that consume them, there will be a better quality as well. For those who wish to keep a crab as a pet, or just care about animals, seeing them kept in better conditions is more desirable. It appeals better to customers on either side of this coin. 
the longer we wait to make change, the more these animals suffer. If you look in the picture, their eyes are all folded down. They are not alert, not interested in moving. Normally, a happy and well cared for crab will seem like they want to explore, interact, and their eyes will be up. They are jammed in together, possibly injuring each other, and starving.