Nokia allowed people to receive 72x14, 1bpp pictures over a series of binary- or hex-encoded SMS messages, and have them show up instead of their carrier name on the home screen. In the 2000s, magazine ads and webpages would distribute them using premium-SMS.
This service, also featuring ringtones, games etc. has been revived, free of charge, by MtF hacker @Manawyrm@chaos.social of the Chaos Computer Club. You can go to Blåmba.de and download all kinds of content into your retro phone.
The service has been discussed in detail at her 38C3 talk: media.ccc.de / YouTube mirror
I also made 10 logos mostly related to Blåhaj, these are already in the Blåmba logo repository.
I welcome feedback and suggestions for future logos!
These are amazing! I specially love the dithering effect you did in the RedHat logo!
Flood-filling with a pattern is very easy on a technical level, even Nokia 3410's picture message editor can do that automatically. You lose half the resolution by area (pixels are basically √2 bigger on each side and in a 45° grid) to get a shade of grey. The hard part is knowing when such a sacrifice is worth it and when not (not often for a height of 14) and to guess or A/B test which phase of the pattern preserves most detail. Sometimes you want more complex dithering or even combined with an outline like the glossy FreeBSD logo.