upload box hinder scroll up down

upload box is hindering scroll up and down in chrome 53 android, as it will slide.

to be more specific, the one sliding when swapped is thumbnail preview.

you can see that yellow box, it's the original location, and it slides to below.

Screenshot_2016-10-09-15-40-48.png

here is another example. it slide to above of original place when I scrolled down.

maybe you can just "turn it off" in smartphone