Scattered heavily across various maps in Battlefield 1, are these oil cans. For a majority of these oil cans, if you shoot at them, a white cross will suddenly appear on them. The most likely scenario is that a developer at DICE changed the texture of the oil can to not have the white cross, and forgot to update the texture that is used for the destroyed model. The static oil cans that are not destroyed when shot at, will instead stay the same, not changing to have the cross. This adds to the idea that this was just accidentally left in by DICE. A bit more interestingly it is possible that this is part of an Easter egg, where you need to shoot at them in a specific order to trigger an event. Adding to this theory is that DICE has not patched this as of yet, despite much speculation in the Easter egg community. This could mean that they have just not seen it yet, or are going to patch it at a later date.