Strange process duration...with a real-time video

[Fredococolin 0]

I often noticed a problem in the estimated duration, have a look on this video (real-time): https://goo.gl/photos/1ii6LZ6X1fzZYgmv8

Any explanation ?

Thanks in advance

[Legendary_zotar 0]

Im not 100% positive what the issue is, and my printer does not have a ETA, but have's Percentage, but what could be the issue is that its an estimate, and its calculating depending on how much filament is left to place and since it is doing a small area (since the other part is finished) its printing faster than expected so its keeping up with the amount of filament left and calculating the time