dvcochran
Grandmaster
Nail on the head.I wouldn't consider them emotional in the literal sense. But they can have the effect of impacting emotion, and IMO you should be absorbed in the form, including in 'feeling' with it, in the same 'feel' you get when fighting. Whether or not any emotional changes should impact the form is a subject for debate, and it can come down to a stylistic thing/the purpose of the form. Mostly I agree with jowga's definition of feeling, with the exception of certain forms that actually are meant to have an impact on emotion; there are some made to either calm you down or amp you up. Most systems don't have those though. I used a calming one a couple times in fencing competitions between bouts when I was doing bad/off my game. Got some weird looks, but it did wonders and let me perform well.
As for performance in competitions. Warning: rant incoming.
Form competition (and learning forms for competition) are anathema to martial arts training. You're often learning not what the form was meant to be, but instead what looks good in competition (and forms have been changed to look good for that purpose). On top of that, you're not supposed to all have the exact same movements/height/etc. When I do a form, how it looks will be different from you, if for no other fact than we have different dimensions. When you try to force those to be the same, one of us (or both) is doing something wrong. It also prevents you from working on new things-if a form requires a kick to the temple, but I can only reach the chin, then we should demo at the chin as a group to make it look better. The issue with that thinking, is that A) everyone else is now doing the form incorrectly, and B) by aiming at the chin, rather than trying to bring it up higher, I'm limiting my own growth. Another example is when people say you should look a certain way in competition, ie: Your kiai has to be at least X loud, your face should show your concentration, etc.. I disagree completely with that. The kiai one I'll address separately since that gets brought up a lot-that defeats the purpose of a kiai. It's meant to be a natural exhale, possibly a forceful one to increase strength/power. It's not meant to be the shout I've seen at competitions. That's trying to look good for the judges, and taking away from the purpose. As for everything else about the emotion you should be showing, or discipline you should be showing depending on who you ask-no. You should be doing the moves properly. And you should be expressing yourself naturally. If that's full of obvious intent, that's great, if it's not, that's fine too. But when you spend time focusing on how you're portraying yourself in the form, rather than the moves you're performing, or how you're feeling in the moment, then you're taking away from the form itself.
One argument against most of the above is that that's just how you perform in a competition, or a demo, not how you train it. I want to nip that one in the bud with two points. 1) You shouldn't have to perform differently than you normally would. If it's a competition-the judges should be well-versed in the forms to know how to evaluate them without needing that, and if it's a demo-faking how you do it is essentially lying to the people watching. 2) You can't just perform something differently on the spot. You have to actively train it to perform in a certain way, particularly at a high level (and competition forms is a high-level skill). So you're inevitably taking time away from practicing them as you should, or practicing something else, in order to get them competition-ready.