I make it look like the embeds, So that people understand that it's a link to my video. Seemed like the best way to help people understand it will bring them to my video, is to use similar language to what's being used on all the other ones. It helps people understand that the picture is a link, that does exactly what it says it does "Activate Youtube".
If I didn't make it clear that the picture was a link to YouTube it would seem dishonest.