I think the concern (if you ever see this comment) is that an attacker will for instance put the fake browser ui around an iframe to a proxy to the legitimate website content using a tool like Modlishka. In that case, whatever is presented to the user in the legitimate application (including whichever superheros or whatever are selected that time around) and all of the bogus images will be presented in the proxied version. Transparent proxies like that are very effective ways of doing phishing because you can phish 2fa or even SSO or similar info by just passing on a legitimate login page to the user but through your MITMed page.