Hello Hodor Hodor !

The sizes of the timeline's thumbnails can be changed via `sys_transcoder_filters` table records edit:

UPDATE `bx_timeline_photos_preview` SET `filter_params`='a:3:{s:1:"w";s:3:"[new size in 100-999]";s:1:"h";s:3:"[new size in 100-999]";s:13:"square_resize";s:1:"1";}' WHERE `transcoder_object`='bx_timeline_photos_preview' LIMIT 1;

Then as usual - clear all caches.