This has been like this for at least a couple years now. Struck me as bit odd in the beginning but it doesn't really improve the chances of brute forcing too much (which is hard on Google login anyways). And potentially saves so much time and server resources
Love the idea! Just some small feedback on your website: When I try to go back from your website, it keeps asking me to login. It's probably due to the fact that it automatically sends me to the /artworks page and when I try to go back it sends me to the / one, triggering the login popup.
Anyway, good luck!