An electronic device according to various embodiments may include: a housing, a flexible display having at least a partial area configured to be drawn out from the housing so that a size of a visible area of the flexible display can be changed, a sensor configured to measure a length of the flexible display, a memory, a processor operatively connected to the memory, the sensor, and the flexible display. The processor may be configured to control the electronic device to: display a first content including at least one image in a first area including a partial area of the flexible display in response to an input, measure a length of the flexible display drawn out from the housing using the sensor, based on the length of the flexible display measured using the sensor being a specified first length, determine that the electronic device is in a non-expanded state, and based on the length of the flexible display measured using the sensor being a second length longer than the first length, determine that the electronic device is in an expanded state. In addition, the processor may be configured to control the electronic device to: based on the electronic device being in an expanded state, display the first content in the first area, and display a user interface corresponding to at least one application and/or second content obtained by converting the first content into a form corresponding to a function provided by the at least one application in a second area including a partial area of the flexible display, drawn out from the housing to be visible, and transmit, in response to an input, data corresponding to the first content to a server connected to the at least one application.