6 - Good. Criticism; if the end of the syringe/needle was more dominant, perhaps with less 'squirt' and more of a trickle, likely make this better in my opinion. Perhaps a variation in lighting also and as this is (presumably) a macro, attention to details like the 'fluff', but minor. edit:wording
Since you didn't put the definition, let me guess: fear of being injected with air bubbles? j/k - it's a good shot. But aren't you supposed to "flick" the syringe to get rid of those bubbles?