>>7647477 (OP)You should try to look at the top picture and the bottom and ask yourself why they look different when you're doing photostudies like this. If you're not able to spot the difference, it's going to be really hard for you to learn. Some people are like that though, their brains aren't well suited for art study. Not to say that art can't be enjoyable for them, but they are not well equipped to improve substantially.
If you're decently intelligent you should be able intuitively pick up a lot of the answers to fundamental questions you'll need to answer when you're drawing from imagination (how to handle different materials, perspective, etc) through doing photo studies with this simple spot-the-difference-and-correct goal in mind.
If you're struggling to improve, or feel like you aren't learning anything doing photo studies with the simple approach of finding and fixing the discrepencies, you're going to need to focus more on asking yourself a lot of questions while you're working and paying attention to the answers.
Familiarize yourself with the categories and practices of study for art (anatomy, material properties, color, rendering, etc.), you likely don't understand any of these categories or others very well but you will be trying to for the rest of the time you're studying art. Always ask questions that help fill those knowledge gaps and study to find the answers.
You're going to be doing these studies the rest of the time you're doing art, professionals do them as part of the process of making their works.
Look at the image, look at your image, ask yourself what is different, ask yourself why it's different, ask yourself if you understand why it looks that way in an image, ask Jeeves if you have to, look and think.
Do this and the drawing will improve.