Just because someone would be offended, doesn't mean that I should restrain from voicing my opinion. It is not being a douche, it is being an adult. Everyone is offended for all sorts of reasons these days, like it is popular or epidemic of sorts.
If someone is to fat or to skinny and doesn't look good in that clothes/costume, it is better to say it, and prevent them from further degradation in public than patting them on the back, congratulating and secretly giggling

I love to secretly giggle behind someones back
Its fun when you try it
Especially when it is a fat bitch in Sailor Moon outfit

I completely agree Scarlet. Nothing happens to you if you are offended! You're just, well, offended... and that's it.

This guy says it much better than I ever could. The relevant part starts at 3:22 but everybody should watch the whole thing because the guy is hella funny and the only metalhead stand up comedian I've ever seen

I would love to say that I am 100% body positive, sometimes it is to much even for me to digest. But that has to be a really horrific, for me to disapprove it.
People should do whatever makes them happy