[System Version]: deepin V23 This request comes after another suggestion I recently created with the same name. There is also a forum thread : https://bbs.deepin.org/en/post/270661 (someone else has confirmed he has the same behaviuour, but we don't know if it is a bug or a missing feature => please help us solve this if this is a bug, or take this as a suggestion otherwise - thank you). [Preconditions]: None [Reproducibility Steps]: Open an app with animated context (eg. video). Place the mouse cursor on the app icon in the dock. A thumbnail of the app content is displayed. [Expected Results]: The thumbnail updates according to the real content of the app window, in real time [Actual Results]: the thumbnail is a still image of what was displayed on the window when the mouse cursor arrived on the icon in the dock. But it does not update anymore.