Hi,
If I understand your question, you are asking why the bar moves with the gallery instead of being stationary on the Screen.
The red/grey/green bar moves with each item of the Gallery because it is inside the Gallery and replicated for each record of the Gallery instead of being made individually outside of the Gallery.
So in your screenshot, the Gallery includes 4 records (4 rows in the database). Each row has data for the name of the item, its quantity in stock, and a LookUp that qualifies the quantity as low, average, good. When you add one button inside the Gallery, the button is repeated for each record using the information from the record. You can set conditions for the Fill of the button to change color based on the number.
