More than half of the MPs in it have been elected since 2015, so there has been a big change in membership in just four years. This partly reflects having three elections in that time but it's also one part of the realignment. The process makes a lot of seats temporarily marginal, as voting patterns shift, and so quite a few seats held by long-serving MPs have changed hands. In addition a lot of MPs have either defected and been defeated or been purged/quit because they don't like the direction their party has taken. There's always the normal attrition but this is higher than usual.
The Conservative party in Parliament has seen a really big change. In particular it now has only 35% of its MPs with a private school education. This reflects both deliberate choice of candidate selection and the kinds of seats it's won (given constituency parties go for candidates that match the seat, usually). It has a quite different kind of social composition and background compared to even a few years ago.
As for the Labour Party the most striking feature is that no fewer than 49 of its MPs sit for London seats. That is more than the West Midlands, East Midlands, South East, South West, and East put together (15, 8, 8, 6, 5 respectively and you could throw in the 1 from Scotland as well). London was easily its least bad performance and the Conservatives' worst in terms of votes and vote share. What was notable was how badly they also did in the South outside London (e.g. in Swindon). That was a surprise to me, I expected them to do badly up North but ok in the SE. That is definitely the Corbyn effect. What this means is the PLP is very clearly metropolitan in its centre of gravity.