That’s because the generated .env file is only of dimension 256x256.
You can generate a bigger file with this PG:
Note however that there is a CORS security problem, you will have to host the file somewhere else if you want to avoid these problems.
I tested it locally to avoid the CORS problems, and with a 1024x1024 environment file you get:
instead of this with a 256x256 file:
Be aware that the environment file is now 8.2Mb, though (instead of 636Kb)!