Vampire weakness clarifications

[Selion]

I'm having hard time designing an encounter with a vampire hidden in a crowd.
The entire shadowless/no-reflections thing seems to me a bit too vague: i'm positive that worn equipment shouldn't cast shadow nor reflection, otherwise a cape could be sufficient to deceive a vampire in most situations, but what if we stress this rule?
For example, if a vampire has a mouse in his pocket (or an halfling on his shoulders, under the cape), will it reflect in a mirror? If a vampire has a black ooze spread on his skin, under his dress, should it cast a shadow?
I know they seem funny questions, but in some game situations things like these may make the difference

[AtlasSniperman]

It might be fun that any object in the vampires possession, or creature touching them sheds no shadow/reflection.

Can you imagine looking in a mirror as a crowd walks past and for a moment you vanish as someone bumps you?

[Psyren]

I don't think their clothes/gear are reflected either. After all, if their clothes could cast shadows, then no one would ever notice that they don't have one unless they were stark naked all the time. And if their clothing isn't throwing shadows, I don't see it floating disembodied in a mirror either.