No, ordinary moderators can't change the icon, only Stack Exchange developers. You should discuss this in the per site meta, and let the Community Manager responsible for the site decide, if he/she agree then it can be taken to the next level. — Shadow WizardJul 2 '15 at 9:26
This is a follow-up to an earlier discussion Feedback Requested: Design-Independent Graduation.
Like the title says, design-independent graduation will go into effect and become our new regular practice the second week of September! All sites which have been waiting in the backlog to graduate w...
@Pandya no, it's not possible to show all user messages in a room, only search. e.g. searching for "pings" gives a result: chat.meta.stackexchange.com/…
@Oded hey, long time no ping! So how is it going? :)
Pixels - the most usual resolution of a favicon.ico icon (though 32*32 and 48*48 are also known in the wild, usually all resolutions living in the same file).