Branding watermark

You upload one square image in Studio, under Customisation and then Branding, and it shows on every video the channel has. Viewers on a computer can click it and subscribe. On phones it appears in landscape and does nothing when tapped, which is worth checking before you build a call to action around it. Timing is yours: the closing stretch, a fixed start time, or the entire runtime. Most channels use their logo mark. A plain subscribe glyph reads faster at that size, and the file has to be square, at least 150 pixels each way, and under a megabyte.