What do I need to look for when viewing a Memory Care facility for placing a loved one?

Use your nose too. If you’re near enough, stop at a selection of different times during the day.

If you smell any odors of body fluids, that represents a significant potential negative.

If there are appetizing aromas at meal times, a real plus.

If attention is given to providing pleasing and evocative aromas (some flowers, fresh boughs of evergreens, sliced lemons, coffee or tea.....) it’s a potential plus too.

The sense of smell is sometimes disregarded. Be sure the scent environment is a positive one.
It is said

The nicest, newest facility probably is not the best. New facilities tend to have problems with keeping staff and justifying having the needed staff for care because of the number of empty rooms/beds.

Look at facilities that have been around for a number of years. Ask about the rate of turnover. Lower turnover would indicate more satisfied staff, so better resident care.

The facility will perform their own assessment of brother to determine whether they are able to provide the necessary level of care. Be honest with the facility about brother's needs.

Many have a fee schedule. Ask how the fees are structured.
I would also look in places where many people do not look. Common area bathrooms, the shower room. Even if a resident has a bathroom in the room often a large common shower will be used as it is easier to maneuver, or a common bathroom might be used to change a brief rather than bringing a resident back to their room depending on what one is closer.
Medicare has a site where they rate facilities. You can check to see what ones are in your area with particular ratings. The ratings might be for Rehab or Nursing homes but many of the rehab and Nursing homes have Memory Care facilities combined.
You could also check with the County or State Health Departments and ask if you can be sent copies of inspection reports. You may have to fill out a Freedom of Information form.

We had to place my Dad quickly when he became violent. I had a friend whos mom was in the AL part of a large chain in my area, and she had been there for over 9 years, happily. So that was plus #1. We toured the MC, it was very separate and a lock down unit. with its own small dining area, and a large open living area with some smaller but still open and bright activity areas. ( plus #2) There were Pt rooms off of this, and my dad was in a small suite sort of thing, with a tiny bedroom and shared bathroom (toilet) and "kitchen" area with a sink, mini fridge and cupboards. And his "room mate" also had a small bedroom beside dads.. so each their small but private space.( Plus #3, and it saved us some $) This was great for us, as he had a "buddy" close by at night, but was encouraged to be in the common areas during the day. There was a good number of staff in the MC area, and the number of Pts was pretty low for that sort of facility ( many more in my MILS MC.. and less interaction) Everytime we went ( and we were pretty much there daily) there was some activity going on.. even if dad was just "reading the paper" or doing things like group talking about their lives. We did find some in front of the TV, sleeping, but for the most part they were kept engaged as best they could handle. ( biggest plus!!) The place was very clean, and the food was fine and healthy, with lots of appropriate snacks . So follow your gut.. Dad liked it there and they took good care of him for his last month. And hospice was able to care for him there.

I have not read the other responses.
Look at how the other residents appear. Are they clean and dressed? Do they seem happy or agitated? Also, visit in the late afternoon after 4:00 to witness "sundowning" and see how the staff handles it.

Are there activities or are the patients seated in front of a TV?
If possible, arrange for your LO's room to be in a quiet area vs. being near the TV room, which can be loud.

Inquire how they keep wandering patients out of each other's rooms.

Ditto to what Glad suggested. My MIL is in Presbyterian Homes in MN. Her particular facility has been there for as long as I've lived in my current home, so since at least 1986. Their administrator has been there a very long time, a good sign. Also, faith-based facilities by large denominations are usually well supported and tend to look at it as a mission. Make sure your brother's NH also offers hospice (and do check this out as well) and accepts Medicaid (in case he needs it). Of course, the facility should not smell and the staff should be friendly and plentiful. We are ecstatic at the quality of care my MIL receives, on Medicaid, from her NH. They have a lot of wisdom and have proven they are well-run. Hope you find a good one for your brother.

Thanks everyone for all the good responses. My husband and I visited a Memory Care Unit yesterday for placement for his brother. We were well pleased with the outcome. Again, thanks everyone for all the advice.

administrator turnover rate is a very telling sign

Also, find out how they handle violent patients.

Where my mom was they called the shower/bathing room a 'spa' which seemed to give it a more pleasant ambience - also it was carpeted in the halls & rooms so noise was so much lower from the other residents but not dining room

If you live in the Atlanta area I would recommend you check out The Memory Center in Johns Creek Ga as a start. It has a lot of activities daily and staff is very caring with all there.