Flying the American Flag upside-down is a sign of distress. For the best answers, search on this site https://shorturl.im/avkuS That America is defeated as a country to Mexico - the very extreme of what you see it as. It has become an unspoken symbol of our fight.
Objects can be easily resized to fit within any space constraints you may have within your document. Select the shape that you want to adjust. Click and drag a handle until the shape is the size you want. HINT: To maintain the shape's width-to-height ratio, hold down [Shift] while you drag the corner handle.
If you have move each of those objects around before you mirror then the objects are not groups or other words locked as one. It's kind of like flattening the objects to one. Then you can manipulate the object as you see fit. Change size, mirror, position etc. Just a tip on grouping. You are group two objects together and manipulate them. Then box the entire graphic and group the entire as one. Remember mirroring is looking away from you from the original. This would made the looking away side the shiney side.