I had a look at the event. What I'm seeing here is mostly what I'd call "formal cosplay". AKA, characters whose outfits tend to look a little formal. Take, say, Sebastian from Black Butler (look him up if you dont know who I mean). He's very recognizable, but he's also a (usually) formal and rather serious character (until a fight scene, that is). Or perhaps characters such as those in some sort of military. The costumes dont look like ACTUAL real-world military outfits, but are military in whatever universe the character is from. An example that I myself have done is Noel Vermillion (from the Blazblue fighting games). Her outfit (the original one anyway) DEFINITELY doesnt look like a real-world military outfit... it's a backless thing with a sort of miniskirt and these big funky ropes trailing from her arms... but it's still a "formal" or "proper" outfit, since it's meant to be a military-ish thing within the world she's from. Have a look at her to see what I mean. Such outfits again, almost always look a bit formal, despite being very obviously "costumes". Or maybe characters who are, I dunno, from some royal family.
In other words, it's a themed cosplay event. A fairly rare thing actually. Usually themed events are held WITHIN anime/gaming conventions, not as the entire event itself. So that's interesting.
That said, with any cosplay-related event, no matter what type, it's entirely up to your own discretion. Anyone that would consider non-formal attire "disrespectful" should NOT be going to a cosplay event of any sort. Cosplay is partly about being yourself, and being creative. If someone is the comedic type and wants to dress up as Deadpool in a miniskirt and a tophat, then they absolutely freaking can.
I say this as someone who has been to many, many, MANY cosplay-related events (as in, whenever I feel like going to one).
If you want to be Batman, then go be Batman. If you feel more comfortable doing the formal thing, then do that instead. Something like this is entirely up to you. Go there, be yourself and have fun. And if that means standing out a bit, well... again, that's cosplay for you. Hell, I"m seeing people wearing bunny ears here. You cant tell me THAT is formal.
Heck I'm even seeing Darth Vader in these photos. And in fact Deadpool in a couple of them. And someone wearing a freaking cardboard box (and someone else with a wolf head in the very same photo). None of this is new to me, but it says something about the nature of the event.
Seriously. Do what YOU want to do. And have fun!
