Use everything that is just inside the black outer line for the thumbnail.
This is the studio thumbnail for @DaSh914 's studio Perfect Parallaxes. The link to the Perfect Parallaxes studio is here: https://scratch.mit.edu/studios/27172379/ I got the font from @FrostyTheParakeet 's project Frosty Fonts: https://scratch.mit.edu/projects/63419610/ . The art is done by me. I'm happy to make tutorials, give help and design or make art for anyone who needs them.