Don't mix 'em
The pattern
This still is filed under Event symbol poster.
Define
A symbol or allegory that makes an event feel like a destination. Not a timetable. A magnet.
Mechanism
Attraction by emblem. Date and venue ride under a picture that already means come.
Verdict
We are filling a room, a night, or a run of dates
Why it works
This is a visual syllogism - two nouns in the foreground, one conclusion behind them - and the argument lands without a sentence of body copy. The skull is built from thin halftone hatching rather than solid ink, so it reads a beat after the pump and the bottle, and that delay is the whole payoff: you recognise the objects, then see what they are standing in front of. The headline is deliberately colloquial and only three words, because the reader is likely to be moving. Two inks plus the paper give maximum contrast at the top where the instruction lives and low contrast in the middle where the threat lurks.
Steal this when
Use this when two things are only dangerous in combination: show both at equal weight and let a third image supply the consequence instead of explaining it. Also the pattern for any warning that must be read in under two seconds.