anonymous galleryIt wants an email address to proceed.
Today people use anonymous picture and video sharing sites called a "chan" site [1]. The trend started in Japan but found it's way to the US and EU. Click at your own peril, some have NSFW content. They do not require an email or login unless one is a moderator. Some of them allow people to delete their own threads and files provided they still have their session cookie.
In my experience if something requires an email address it is neither anonymous nor will most people bother aside from playing around with it to judge the html / css / javascript.
[1] - https://allchans.org/