Seen this small black& white bird in Seaford East Sussex today but sure it’s not a wagtail…

Terrible pics I know - it was very stormy and couldn’t get a decent image as being battered by wind.

its right on the beach, and I’m sure it is not a wagtail that’s why it caught my eye. No long tail and just fatter if that makes sense! Im a complete novice but I need to know now..

It is very hard to spot in second image and out of focus but its there..