"This could be a lengthy answer but I'll try and keep it short.
The site is winding down. When the owners got rid of the chatroom, I would imagine the overall disk space they hold on whatever server has also decreased. This means the site capacity for holding/storing data, in whatever format has been reduced. To compensate for this, they will have reduced the maximum size, in kilobytes a picture can be when uploaded.
Devices these days, take bigger and bigger (in kilobytes, remember) pictures because they are able to with advances in technology.
Somewhere, at some point - probably when they reduced diskspace, the lines between size vs capacity have crossed and gone out of kilter.
You need an app that reduces the picture size to less than 1mb (1000 kilobytes), or set the camera to take smaller pictures."