If used, a visual concept or metaphor should be appropriate to the brand and the site's audience.
Flowerbud.com has flawlessly executed a very literal metaphor. Referencing the watercolor sketches of gardening books and antique floral shop paraphernalia, the site could easily have veered to the wrong side of kitsch.
E X E C U T I O N
Concepts should extend to the details.
All the details of this site are just right. The header looks like it was torn from a flower shop ledger and the typography is drawn from botanical prints and specimen labels. Even the prosaic "out of stock" notice is given the appropriate twist.
C O N S I S T E N C Y
If a metaphor is used, it should be used consistently throughout the site.
A non-commerce section of the site, "Mark's Journal," has a slightly different treatment from the rest of the site. With the visual language of field notebook, it is completely in keeping with the concept used throughout.