When we travelled into the UK from France, our border force said it didn't matter that our 3 1/2 yr old DD doesn't look anything like her photo (taken when she was a week old and doesn't even have her eyes open). The main reason for the passport is to ensure she is travelling with her parents.
We came back into the UK in December from Finland and our border force said completely the opposite! He said we need to renew early (despite having 2 years left) as she looks nothing like her photo and if we were to travel out of Europe they might not let us in to whichever country it may be. Though we did travel to Dubai in April and didn't get stopped.
Has anyone else been in a similar situation? I loathe renewing early as they aren't cheap and it isn't my fault the passport system allows this to happen. If this was a problem surely they would only run baby pasports for a year. They allow it to run for 5 years so it shouldn't be a problem as far as I am concerned.