Since 2006, Cartoon Network operates a second channel in the United Kingdom called Cartoon Network Too. When Cartoon Network launched a new global logo in 2010, that didn't apply to Cartoon Network Too, which continued using the previous logo, that had a extra blue box with the word "Too" added.
Apparently, it was hard to figure out how to attach "Too" to the new logo, as the inconsistency wasn't fixed until last week, when Cartoon Network Too finally updated its visual identity to match its sister channels. The channel now uses a series of logos where "Too" is seen in a container shape attached to the Cartoon Network logo. The blue version above seems to be the main version, but there are also variations with different shapes and colours, as seen below.
Update May 23: The new logos were created by The Grid and Rob Clarke. The shapes should represent different programme genres.