An end-user choosing to go to <https://wikipedialibrary.wmflabs.org/users/update/$$$$/> where $$$$ is anything other than his own-numID; gets denied very rightfully.
I have no idea as to why the messages and the random photograph are displayed in a left-aligned manner, which creates a huge amount of white-space on the right side and is severely unimpressive. Please center-align the display. Center-align is advises against in case of paragraphs et al, but here it's perfectly suitable and soothing for the eye. The design team may be further consulted.
At any case, the attribution of the photograph is implemented in an equally ugly box. Even importantly, vital data is missing. I was shown [https://flic.kr/p/6wL7Sc this photograph] and the box below contained:-//crunchie needs a little tin cup by frankieleon, on Flickr; CC BY// No clue where the 2.0 went. The non-capitalization of the starting letters is equally distasteful, though I will blame the orig. uploader/author.
The same case of missing parameters and white-space is visible over all 404 errors; in the page displayed, if someone clicks a link for a partner who is not anymore in the platform. Click the link over T218848.
Finally, who is [[ https://www.flickr.com/people/armydre2008/ | frankieleon ]], whose images are specifically displayed in all such cases? The closest that a GSearch boasts about is a footwear company. FWIW, there are ample photos over our own Commons; which can be displayed over those situation and under far broad licenses, truest to our principles.