What makes a shadow?

I couldn't see what all the fuss was about. No, really, I just couldn't see it.

The group, clad in their regulation white coats, stethoscopes conspicuous in the junior ranks, huddled closely around the bright white lightbox as image after image was clipped to the display.

A lot of tapping of pens on images and earnest nodding took place as a consensus was reached. The group turned towards my bed, parted, like a murmuration chased by a hawk to reveal the consultant, in immaculate Saville Row pinstripe, who bore down on my bed.

"Next time, please don't swallow the thermometer"