Rhona Mitra is at best a C-list star (maybe B-List in Britain). Sure she's been on The Practice and Boston Legal, but I doubt she's a household name (especially with that name). I guess that's probably why she decided to do this photoshoot. I wonder if there are celebrity photographers out there who advertise in the newspapers with ads like "Is your career stalling? Would you like more recognition? Do you have big boobs?..."
ps - Kelly Brook is also British and Naked.