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.
this one is alright (if you like having your monitor blind you with lumo green light!). i tried it out on my desktop and its just too bright! but otherwise its a pretty cool design. my only other objections is that the photoshop brushes arent meant to be so big and it looses quality on the full size version.