I decided on a little experiment. To be honest, I did have quite a good idea how it would turn out, but I decided to make it an experiment nevertheless.
I posted similarly processed iPhone shots in the Gallery and in a blog post, both with a title that indicated it was taken with a camera phone and not with a 'real' camera (that is to say, the Snapseed Snap title of the Gallery photo would be an indication of that for many iPhone users).
Both were colourful holiday snaps, taken with my iPhone, and processed with Snapseed - in fact, very similarly processed.
The gallery photo has had 25 viewers and 11 voters since yesterday morning, and the blog I posted around the same time has had 326 views and 1 EPZ like.
I think it's safe to say that if a photo isn't spectacular as a thumbnail, it may well get more 'exposure' (pun originally not intended, but a nice bonus) in a blog post than in the gallery.