User blog comment:Waters Knight/Weiss killed 'herself' in the White Trailer/@comment-182.55.85.113-20131214044213

An alternate interpretation could be that the reflection we see could be the mirror's(knight,giant armor) answer to her question "who's the loneliest of all" which is Weiss herself "I'm the loneliest of all".

Furthermore the Knight/Giant armor/Mirror shattering into many pieces after being defeated and the characters alluding to their fairy tale counterparts(in this case Snow white) seems to support this theroy.