zulip/web/templates/settings/add_emoji.hbs

<form id="add-custom-emoji-form">
    <div>
        <input type="file" name="emoji_file_input" class="notvisible"
          id="emoji_file_input" value="{{t 'Upload image or GIF' }}"/>
        <button type="button" class="button white rounded" style="display: none;" id="emoji_image_clear_button">{{t "Clear image" }}</button>
        <button type="button" class="button rounded" id="emoji_upload_button">{{t "Upload image or GIF" }}</button>
        <div style="display: none;" id="emoji_preview_text">
            Preview: <i id="emoji_placeholder_icon" class="fa fa-file-image-o" aria-hidden="true"></i><img class="emoji" id="emoji_preview_image" src=""/>
        </div>
        <div id="emoji-file-name"></div>
    </div>
    <div id="emoji_file_input_error" class="text-error"></div>
    <div class="emoji_name_input">
        <label for="emoji_name" class="modal-field-label">{{t "Emoji name" }}</label>
        <input type="text" name="name" id="emoji_name" class="modal_text_input" placeholder="{{t 'leafy green vegetable' }}" />
    </div>
</form>