Google storage usage on two accounts are counted different

Question

I have two google accounts and about 1GB uploaded photos on each. I see that on my first account photos use storage, but on another no (0% used of 15GB). All photos are max 1600 pixels width/height. What is going on ?

First Google account

Second Google account

UPDATE

I saw that on first account i don't have a something like "Profile"(accessible on url https://profiles.google.com), I see only Join Google+ button. However on the second account i have a profile, but I have to notice that on both account Google+ is deactivated - when i go to https://plus.google.com i see page Join Google+ by creating your public profile. Strange, what is this profile on the second account where GPlus is off ?

First Google account

Second Google account

Answer 1

This Google Support article should help answer your question. If you upload photos through Auto backup as full size images (the default), they count towards your usage. It also appears that when you are manually uploading the same logic is used.