Wouldn't recommend a wallpaper focal wall. Will say the wood tone and style of the bed headboard seems somehow out of place. Can't quite put my finger on it. A white painted headboard might work better. Might also suggest the headboard be a bit taller. It could be the bed placement that doesn't seem right. Is there another wall the bed could be placed on.

Remove everything from the dresser top and the side table by the bed (except for a lamp with good light beside the bed). Hang the tv. Visitors need a place to set their stuff - they have minimal interest in your stuff.

Is there a folding suitcase stand, like you see in hotel rooms?

If you are considering painting, I’d cover the dull gray with a soft off-white.

The bedding is where I usually start a bedroom decor So some with the color of the wall if no painting will be done . The art can go for sure the dresser with nothing on it. I need a to scale floor plan show windows , doorways where those lead and every measuremnt clearly marked so we can get a feel for the space . I do not have a dresser in my guest room since a small chest of darwers in the closet is really all that is needed . Yes to folding luggage rack, night table with lamp for reading and once we have the plan we can help more. I do not think a TV is amust since most have a laptop for viewing.

Vibe - I can't totally understand your style. Can you give us more hints. The furniture is dark and heavy as is the art, but the colors you like are light and springy, as is the desk and chair. You can use everything in here now, but need to figure out how to style it to make a cohesive look.

Accent color - The carpet is sucking the life out of the room. Use the dark gray to your advantage as an accent color so it looks intentional. Dark grey trim on pillows, dark grey throw. Or, if you want printed bedding, go for some with dark grey.

Lighting - Bed looks smashed against the desk. Move it slightly to the right. Hang plug in wall sconces on either side of the bed. It will add enough interest to this wall and provide light. Remove the bunny lamp, which is odd and squashed into the corner. Get sconces with a fun shape to catch the eye and counter the heavy bed frame.

TV - Does anyone actually watch that small TV in here? Who says here? People with laptops who aren't watching TV anyway? If someone actually watches it, hang it on the wall to the left of the dresser.

Dresser - Clear the dresser. Leave it empty with a nice tray for people to unload things on to. Hang the bed art above the dresser if it is a piece you really love. I'd consider a mirror above the dresser.

Add some texture and shine into the room. A bit of brass. Silky and rumpled fabrics.

Be sure to add wall hooks for bags, purses, jackets, and easy access outlets for charging phones and devices.

NO accent wall in here. Not a painted accent wall or wallpapered. You don't need a pop of decor on a wall. You need an entire scheme for the whole room that works together.

Please put a bedside table on both sides of the bed. I stay sometimes with a friend who has no bedside tables in her guestroom. Always a hassle to find a place for my glasses and book.

I'd slide the bed toward the doorway a little (Maybe 1-2 feet) to make it feel more balanced and less cramped. I never hang a picture over a bed like people do. My nana met a lady on an airplane that lost an eye when her picture fell off the wall! I can't get that out of my head. You can hang a macramé something or a textile above instead. I am not apposed to a fun wallpaper behind the bed. I would first choose bedding you love and choose a wall color from there, like previously suggested. Add a mirror above the dresser. Hang the plant? Maybe a floor lamp between the bed and desk to use for a nightstand/reading light at night and desk lighting in the day. If there is room, you can mount that tiny TV, but at that distance, it is pretty small. Maybe don't even bother with a TV?

How big is that room? Is that the only way the bed can go? I would skip the picture above the bed - it seems off because of the window. Some beautiful drapes on the double window would look really great.

I love the lamp!

My nana met a lady on an airplane that lost an eye when her picture fell off the wall! I can't get that out of my head.

I don't think I will ever get that out of my head either.

I think there is nothing wrong with the layout of this room. Great dresser nook, great use of small desk as a bedside table.

The color you currently have on the walls works well with your sample colors you like. This room feels great as it. It just needs styling to pull it all together.

Above the bed: Add a large framed print, woven wall hanging, or a minimalist gallery of 2–3 pieces. Themes like botanicals, abstract shapes, or landscapes work well.
Opposite wall (above dresser): Hang a mirror or a framed artwork to visually expand the space and add charm.

About pillows.

Use three layers:

2 large euro pillows

2 standard pillows in shams

1–2 decorative accent pillows in patterns or velvets to add visual interest (earth tones, soft greens, or subtle stripes).

Add a diffuser or candle in the dresser corner for a cozy, welcoming aroma.

Some inspro

If privacy isn't a concern, consider sheer curtains on top of the blinds to soften the light and frame the windows. Go for off-white or flax linen for a breezy feel.

Or you can use bamboo blinds as well with sheer curtains.