Poetic metaphors puzzle me. First it was 'Elegy written at a church graveyard' and now it's 'Blowing in the Cheese' How does cheese blow?

For Rodgers:

"he boast of heraldry, the pomp of power,
And all that beauty, all that wealth e'er gave,
Awaits alike the inevitable hour.
The paths of glory lead but to the grave."