This award-winning photo (Captured by physicist David Nadlinger) shows a single Strontium atom trapped between two electrodes. ​The atom is blasted with lasers, causing it to absorb and re-emit light so intensely that it becomes visible without a microscope

Well you can’t see an atom with a microscope anyway because it is smaller than light wavelength. Hence all this.

That dot isn’t the atom’s size, it’s thr light it’s throwing off. The atom’s held in place with an electric field, blasted with lasers, and the glow is what the camera picks up.