kāye kāyā-(a)nu-passī viharati,
1. He meditates continuously seeing the body as a body [as it actually is]...
A picture from Ajahn Maha Boowa's manual on asubha practice.
It's in Thai, so I don't know what the instructions actually say, but from what Thai Forest meditation masters with strong samadhi say from their personal experience, when you walk around seeing people and living beings, samadhi is so strong that in real time you can superimpose xray vision of what's under their skin.
Even without supernormal imperturbable fourth jhana level of samadhi, you can mentally visualize what's under the skin from images of body parts you've previously memorized.
What's most helpful about this practice, is you get in the habit of doing jhana, samadhi, asubha all the time, on whatever living beings come into your field of vision, and it starts to become a habit, your new 'normal'.