The "see you again" emote (/･､)_┌三ﾟ+｡*ﾟ is typically used to express a feeling of sadness or reluctance when saying goodbye, but with the hope of seeing the person again in the future. The "Bit Sad Good Bye" emote may refer to different emoticons depending on the context, but generally conveys a similar sentiment of being sad or upset about parting ways.