"Whoops! You're out of space. You are currently using 100% of your 1 GB quota for photos. Upgrade storage
Photos are stored in your Picasa Web Albums account and are included in your 1 GB free quota for photos. Additional storage that you purchase is shared between several Google products and is in addition to your free quota. Learn more"
Of course, it would be best to use the snipping tool and publish here a photo of the screen, showing this message from Blogspot, but, apparently, I can't.
So now, if I want to upload photos to my blog, I have to upgrade storage, which means, I have to pay money, which I obviously won't do.
My final decision will be announced later, when I've made up my mind.