On the whole, yes of course, since it could potentially be read by a billion people, which is 'mass'.
In actuality, it is read by a few hundreds a day, at most - probably (I mean actually read) - about the same number I could lecture to without technological aids (if the lecture theatre was well designed).
But the main determinant of whether this blog counts as 'mass' is in the behaviour of the reader.
Is reading this blog part of a large trawl though other blogs and websites; or is it a specific, deliberate and much more focused thing.
If reading this blog is just one element in trawling the web, or marinating-yourself in the internet, then it is indeed part of the mass media - even if only six other people are reading it.
Are you plugged-into the mass media?
I sometimes think that the main difference between pseudo-Right wingers (such as libertarians and neo-conservatives and 'manosphere' types) and real reactionaries is indicated by whether they are plugged-into the media, or not.
On this analysis, if you life is dominated by the mass media you are a creature of the Left - and this is not affected by the nature of the media content.
A self-identified 'reactionary' who spends several hours per day engaged with 'reactionary' news sources, magazines, blogs and the like - is actually a Leftist.