OK, a far out explanation, that would be consistent with what is known, would be an iron particulate formation from blood disorders related to severe clotting. It is probably a hoax, but there is always a scientific explanation, if true.
It looks to me magnetic nanosensers are a reality. Whether they cause magnets to stick to the inoculate site I neither know nor care.
There is at least experimentation going on involving magnetism and nanosensors. Whoever got inoculated got experimented on and could be part of the any ongoing experiment associated with the scamdemic.
You should have considered that before you dropped trou and bent over; but maybe you believe politicians bureaucrats and medical experts wouldn't lie to you.
From https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7526334/
Magnetic-Nanosensor-Based Virus and Pathogen Detection Strategies before and during COVID-19
Among other biosensing technologies, magnetic biosensors have attracted special attention in the past 20 years. Both surface- and volume-based magnetic biosensors have been developed for the detection of viruses, pathogens, cancer biomarkers, metallic ions, etc.32−42 In magnetic biosensors, the magnetic tags [usually magnetic nanoparticles (MNPs)] are functionalized with antibodies or DNA/RNA probes that can specifically bind to target analytes.43−45 The concentration of target analytes is thus converted to the magnetic signals that are generated by these magnetic tags. Compared to optical, plasmonic, and electrochemical biosensors, magnetic biosensors exhibit low background noise because most of the biological environment is nonmagnetic.