Interestingly the old Beaches-Woodbine was a solid NDP riding since 1975, the north end, was Don Mills (East York plus but included areas now in Don Valley East and West) was more PC. Now, since about 2011 Beaches has trended OLP. in 2014 the NDP lost BEY because you can see a very noticeable N/S split; NDP winning the north, East York and the OLP winning the Beaches in the South. Still a bit swingy I feel, but there is a stronger OLP base then previously, due to just how expensive and NIMBY the area is here.
Yeah, if you look at incomes, transit usage and so on the Beaches looks more like North Toronto by the lake or something. It's not "hipster" gentrification at all, but liberally minded accountants and the like (a lot of "better educated than paid" people).
The west end has more renters, a younger population and is hipster central - so more to the left politically. More contract faculty or young journalists working for Vice or something.