From Shutdown, I held Command/Option/Shift/Power ???

What have I done? From a full shutdown, I mistakenly used the following key combination, held down Command+Option+Shift+Power until past the startup chime and the Apple logo. Without realizing, I let the notebook finish the bootup/startup, which took a bit longer than normal and. After, I sensed my computer was not the same. Better is some regards, not so in other. So far, I have noted the following: 1) it is faster with starting up, launching apps, and shutting down; 2) everything seems bigger and a little zoomed in, as in text, icons, backgrounds, pages within windows, etc.; 3) despite having shutdown with various apps left open, with a subsequent start up, Finder is the only app that launches; 4) once-in-a-while the whole screen does like a flicker, a very fast but slight zoom in/out. I fear the list is going to grow. I have a MacBook Pro 15 inch, early 2011, running Yosemite 10.10.5. I have been searching all over the internet but have not found a definition, not even a mention. for this particular key combination. I was trying to reset my SMC but got the Command and Control keys mixed up. OMG ... What have I done?