LTU932 From Germany, joined Jan 2006, 13864 posts, RR: 51 Reply 1, posted (6 years 5 months 1 week 6 days 10 hours ago) and read 1883 times:
They're not different. Just that a great part of the cockpit window frames were painted white to colourmatch the fuse. Sometimes an unpainted one can appear if it had to be replaced before a D-Check or a visit to the paintshop, so what you see is perfectly normal, at least for BA.