gzip compressed (binary) pbm is only 56 bytes; 32 bytes for zstd compressed data. PBMs have a very simple header and no footer, so the file is almost entirely all zeroes.
Web browsers do not support pbm, last time I checked. On the other hand, the JPEG-XL rollout is well underway (e.g. Chrome supports it behind a feature flag).
The image is only 22 bytes as a jxl:
https://cdn.discordapp.com/attachments/286612533757083648/96...
base64 data uri version: