It might mean something - instagram is probably used more by younger people, which tend to vote Labour more. Also the young Labour movement is better at the 'social media game' in general, in my overall perception. I don't think the actual numbers are representative though.
Well not that it means anything, but on Instagram #votetory only 1000 posts, #toryscum has 5k plus and #votelabour 101k plus. (Not all of them by me)
I also logged into my Facebook for the first time in 2 years last night and didn’t see a single Tory advert WTF is going on.