Bacon fat...I guess he's trying to give the birds heart disease.
Its common to give wild birds fat like this, suet which is the hard white fat on the kidneys and loins of cattle sheep and other animals is packed with seeds stuffed into it. Its a big seller and available in all the stores I shopped in when I lived in Nova Scotia.
Suet blocks are a big hit with wild birds especially woodpeckers who would show up in the front yard to have a munch in the colder winter months. The fat helps them keep on weight to stay strong in the harsh winter.