taking photos in a holder is not easy. lighting and glare are the biggest issues. you can try this and see if it helps at. the first set of photos are close but just a little too much glare and focus can be sharper.
i think if its graded VF25 that its generous even though these had all kind of strike issues
1. if coin is in holder, remove coin from holder if possible
2. turn off flash
3. place coin on flat surface with indirect natural light. maybe a window sill in a cloudy day. Use a black or white background to avoid any reflective color
4. move phone about 3in from coin
5. zoom in using your fingers until the coin comes into focus and fills the cameras view finder. if your phone has a portrait selection use that and then press and hold on the coin in the view finder to AF lock it
6. hold phone steady. if you cant then place something on either side of the coin (like books) at that distance and lay phone between them. this will hold it steady and allow you to zoom and take the photo without any blurring