Just thought I'd drop in as you're getting very close to what I do for a job there... I'm sure you see what you see but I can guarantee there is no 'positive discrimination' when dropping those images onto banking websites. In general through a web journey we will try to ensure those of all backgrounds are represented at some point, it's nothing more than that. The average employee running these sites are just average people like us - it's not as if there is any direction coming from the top in terms of showing those of particular ethnicities more than any others. The only thing I'd say that is pushed on occasion is LGBT but only when it's relevant or topical (i.e. the organisation is running a campaign, etc).
in 5 months of 6 the dominate ethenicity was of 1 ethnic background with 2 or more "family members" same ethnic group also featured in majority of other "days" with just a handful of others to complete the cycle! there has been media coverage of "going over the top " which lessens the point being made about the ails of 1 race! …… I would sooner not see anything other than the page of script to allow me to log on and do my business ...afterall I am already signed up!
Fair enough mate, I can't speak for that bank but certainly in the other financial institutions I've worked at, I've never once been told to do anything like that.