Startup competitions are different from regular investor pitches. Your are on stage to deliver a show to a crowd, not to a VC partner group. The jury members do not have to put their money where their mouth is. I asked a recent jury member for such an event to list feedback on investor presentations from the top of her head, without too much thinking. Here is the raw result:
Have someone speak who masters the language. This is a back-to-back show, and if all candidates speak fluently, the one who does not will stand out negatively.
Personality, attitude, enthusiasm, passion are far more important than professionally crafted slides.
If you have to send a very junior team member to present, because the you, the CEO, has better things to do than to attend the startup competition, it is probably better not to show up at all.
Contradicting myself, a presentation by (recorded) video was received remarkably well.
Startup competitions might suit some startups better than others. Things that score points for a big crowd: an unusual, non-typical, entrepreneur; an impact/green/environmental/healthcare-related company objective, a market that a non-technical audience can relate to, etc. etc.
When preparing for a startup pitch event, customize your slides and story and don’t bring your standard investor pitch to the event.