The phrase "bit of a dip" is an idiomatic expression that means a small decline or decrease in something. It can be used to describe a temporary or slight drop in something, such as the stock market or a person's mood.
The most eye - catching feature is the little contour at the top of the screen which houses the front facing camera and is essentially a little bit of a dip into the notification area. (androidauthority.com)
Flow of funds loan data on bank lending show a bit of a dip since the IOER has gone up, so maybe there's something there, but there's simply no correlation between these variables (the IOER rate and credit flows) since the IOER program began in 2008. (jaredbernsteinblog.com)