Bumblefoot (Pododermatitis is an infection of the footpad, most often, due to the gram-positive bacteria group staphylococcus. It can be set on by several issues, but most predominantly in poultry, you're going to see it related to rough perches or poor environmental substrate promoting erosion of the epidermal surface, allowing penetration of bacteria from the environment.
With your bird, the infection looks fairly spread within the plantar surface considering the swelling. Treatment for bumblefoot will vary with the severity, and how one chooses to deal with it, but oftentimes, soaking the foot in a salt, or antiseptic mixture to loosen the eschar, then taking it out with a scalpel, or pair of tweezers is sufficient. Frequently, puss and caseous material need to be squeezed out during the surgery as well. Application of an antibacterial ointment or cream such as silver silvadene, or Neosporin, and bandaging done on the foot to prevent subsequent reinfection if suggested as well until the wound is well healed.
Yes that is bumblefoot infection, and there seems to be the early signs of scaly leg mites, because of the slightly raised scales. I would start with some warm soaking of the feet with Epsom salts water daily. Some use Betadine soaked gauze pads with sugar (sugardine) taped to the foot for a couple of days to help treat it. Others use PRID drawing salve. I usually just do the surgery if there is any limping or a lot of swelling. Here is another good link to read: https://the-chicken-chick.com/bumblefoot-causes-treatment-warning/
@Eggcessive thank you! I will be starting salt baths. She doesn't seem to be limping. You said the raised scales are a sign of leg mites? What would that be caused by? And I would assume they could spread to the rest of my flock?