Cool tool, I just downloaded the release to check it out.
I ran it from a terminal in which I have http_proxy and a few other proxy-related environmental variables set, and the window says "This is an HTTP CONNECT tunnel, not an HTTP proxy." The page showing this text is coming from the HTTP CONNECT tunnel as a rejection to an attempted proxy connection. If I remove the variable then the firewall won't let it connect anyway, and it doesn't show any emojis. Does EmojiTinyPicker need to connect to the internet for something, like to download emojis?