Hi @Rita2164 .I found your question interesting, as I'm a home stager. I'm also an American, so my opinion may be different than what is "standard/typical" in England. But here's my recommendation, although it comes with these caveats: 1) I don't know what the room looks like, 2) other accessories you have in the room or 3) the color of your bedroom bedspread, etc. I would put the picture over the bed, but NOT high up the wall. The standard rule of thumb here is to place the picture approximately 6 - 8 inches above the headboard, as it tends to tie the bed/headboard/picture visually together. You can use screws through the picture
frame (a long as it's not a priceless antique) to secure the picture to the wall if you are concerned with it falling off, hitting your guest(s) in the head! Not a great way to start off. ; - ) Also, it's visually more appealing for the artwork to be at least 1/2 to 2/3rds horizontally the size of the bed/headboard. You don't want a small 12 ' x 12' single picture above a full or queen/king size bed. It will look out of place and inadequate.
You may be wondering, why does she say this? Well, in most nice hotels, you will typically see pictures over the bed. If most national/chain/franchised hotels, use highly skilled Interior Designers to design their rooms, it makes sense to copy their successful formulas. That being said, if I had my preference, I would also consider using a nice, pleasing picture on the wall across from the bed, also. It gives them something to look at upon waking. You might want to mount a TV on this wall if your room can accommodate it. Ultimately, it's your decision and must work for your individual situation.
Best Regards,
Sophie