Electronic device comprising flexible display and operating method thereof

An electronic device comprising:

• a first housing;
• a second housing connected with the first housing and configured to perform a sliding operation;
• a driving device, comprising a motor, configured to adjust the sliding operation;
• a flexible display comprising a visually exposed area on a front surface of the electronic device that changes in size in response to the sliding operation of the second housing;
• at least one sensor;
• memory storing instructions;
• and
• at least one processor comprising processing circuitry configured, individually or collectively, to execute the instructions and to control the electronic device to:
• obtain orientation information of the electronic device using the at least one sensor;
• in a state in which the exposed area of the flexible display corresponds to a first area, display content and a letter box on the first area;
• based on identifying a full screen event based on a user input, determine whether an orientation of the content and an orientation of the electronic device are the same;
• based on determining that the orientation of the content and the orientation of the electronic device are not the same,
• change the orientation of the content so that the orientation of the content and the orientation of the electronic device are aligned;
• identify a size of a second area, which is a display area corresponding to a size of content enlarged while maintaining an aspect ratio of the content until the letter box is removed;
• change, using the driving device, the exposed area of the flexible display to the second area;
• and
• display, on the second area, the enlarged content.