Last week, having redesigned the Lightbox feature, Blogger released it for a second attempt.
Thanks to your feedback, we turned Lightbox off temporarily, and we’re re-launching it today with the option to disable it, along with a handful of fixes to bugs that you reported.As with any Blogger feature, it now deserves a closer look.
Lightbox is now provided as an option - "Open images in Lightbox". In the Classic GUI, it's selected in Settings - Formatting; in the New GUI (2011), it's selected in Settings - "Posts and comments".
When you click on the image to the left, you will get an overlay, which covers the post display.
As with various similar Google photo displays, you look for the white on black "X", in the upper right corner of the window. Click on the "X" to return to the blog, as previously displayed.
Blogger has stated that the setting enables or disables it for the entire blog.
we've also created an option to disable it per blogSeparately, they also stated that the setting is disabled, by default. You might do well to check your setting at least once, as some folks have found the setting enabled, by default.