This is similar to the election in Australia just after Julia Gillard took power from Kevin Rudd. Basically to quash the people complaining that she didn't get voted in and just usurped power instead.

It is also a move to counter the very real threat from SNP.

I don't see how it does that, In effect it makes them stronger by giving them a general election she gives them an indyref. All her arguments against one fall away.

Yes exactly, it is IndyRef lite! She is hoping they lose, thereby negating calls for IndyRef proper. I din't say it wasn't going to backfire spectacularly. I think the whole thing is a huge mistake. Brexit is happening, Article 50 has been triggered and is irrevocable. Unlike the rest of UK, Scotland still appear to have a choice. I can't see how the Tories ever thought this was going to end well.