Bumble foot???

I’ve seen a lot of posts about “bumble foot” and I’m curious to what it is? My chins don’t really let me get close to their feet often. Today was the first time I’ve seen and been able to get super close to my chins feet. I never really thought much of the posts till now when I see tacos feet.

I tried to get as many pics as I could. Is this bumble foot? What can I do to help? They look so dry