Choose the caption bubble to begin. If you want to upload a custom bubble or alternative image then submit the caption first, then edit the comment and attach a "Place img". Once the image is approved you can use it by editing the caption again.
you can see on the floor 2 small piece of scotch, he always takes his marks, the keyboard should be 10 cm from the table, mousepad like that, and that was really hard for him to go and play on the small stage where he had'nt his 'own' marks, so we had to move his table on the stage :)
I've been using my mousepads like that for years before I saw anyone else use it that way. It was just more comfortable and more accurate for me to have my wrist and my mouse on the same resting surface.