QGC 3.4.3 does not always show pics for Drone Sensor calibration

I ran into something very strang.
On QGC 3.4.3, when I click on Sensors to calibrate the drone, I do not always see pics for the drone position. Sometimes I see text which is really hard to follow.
Is there any setting to always see pics to place the drone in during calibration ? Is this specific to some QGC versions ?