I just noticed this
I opened the question to see what the modification was. But I saw that neither the question nor the answer had been modified recently. I was about to post on meta to find out what had happened, but I checked the revision history instead. There, I noticed that it said "Bumped by Community user". Turns out it's a cool feature to bring exposure to certain questions (those that fit certain criteria which suggest they may need exposure.)
Or maybe some other, more suitable word. But not "modified" since it is in fact not being modified.