Did it keep the photo from loading?
I can still click through and get the same web page everyone else does.
In the past, all the warnings came on websites I was not familiar with, usually sites I had clicked on because of interesting photos or headlines.
My guess - your site is fine, but some quirk in its code set off McAfee.
Just in the last few weeks McAfee has started blocking ads on a number of sites I use, like Daily Caller and even Drudge from time to time.
There is probably some new software protocol that “safe” sites are supposed to use, but the smaller sites with limited funds have not got around to installing the update yet.