Salad Fingers is quite literally the last remaining person on earth, or at the very least his own part of it. It lives in a desecrated corner of nothing. (It because i'm certain it is a hermaphrodite) S/He being alone has naturally succumbed to a degraded sense of surrounding, S/He has created everything in it's own mind. everything it has done up to this point has all been in it's own head. In short Salad Fingers is living it's life inside out, by which i mean it's thoughts are seen as others actions, not thought it's self. It has taken it's own loneliness and created a external world. and it was in this installment that it finally broke down and lost it, hence the tears.
Okay but honestly i only belive and/or know half of that the majority was filler, heres my acctual in short opinion
Salad Fingers Is scary as all hell -Fact- it's very entertaining -Fact- and S.F. is completely alone which has transferred into total Psychosis and a mental brake down. This installment was the last nail to the coffin for this analysis.