No, Divine Sense won't allow you to hit it as if it was visible. Invisibility says that:
Attack rolls against the creature have disadvantage,
and the creature’s attack rolls have advantage.
and Divine Sense does nothing to change that. So what's the advantage of sensing them? Well, the advantage is that you sense them. If you use Divine Sense and discover that you're surrounded by undead and fiends, isn't that better than not knowing?
You could make the argument that if you knew to use Divine Sense, there wouldn't be any point to using it. This isn't really true, though: there's a big difference between knowing that there's something lurking nearby and knowing how many, where, and approximately what creatures are lurking nearby.
Finally, the most important benefit: knowing where it is means that you know where it is. This allows you to use spells like Dispel Magic to remove its invisibility, or just spells like Fireball to hurt it and invisibility be damned. For that matter, you said that you still have disadvantage hitting it, which is true, but at least you can try to hit it. (If you didn't have Divine Sense, you wouldn't even know where it is, you'd just have to swing your sword at a random square and hope. Unless you hit, you won't even know if you guessed right.)
Did you call it right? Sure! It's your job to bend the rules or those you don't agree with to make it fun and enjoyable and reward clever tactics.
Did you do precisely what the written rules dictate? No.
Here is why:
Divine Sense
Until the end of your next turn, you know the location of any.....not behind total cover. You know the type of being whose presence you sense, but not its identity.
'Location' or: A creature's 'Space' PHB pg. 191
A creature's space is the area in feet that it effectively controls in combat, not an expression of its physical dimensions. A typical creature is not 5ft wide, but controls a space that wide.
Mirror Image
Three Illusory duplicates appear in your space. The duplicates move with you and mimic your actions, shifting positions so it's impossible to track which image is real... A creature is unaffected if it can't see, if it relies on... blindsight or if it can perceive illusions as false, as with truesight.
Now that I've cut these down to the parts we should be paying attention to, we are left with the following conclusion with no real argument to the contrary:
A humanoid celestial angel is perhaps 2 foot across in width, but it controls a space of about 5 feet. That's its personal space, its combat space. A humanoid is not 5ft wide folks. This is its location. That particular 5ft space within its control.
Mirror Image places 3 illusory images of that same celestial in that same space. The same location. They move with the celestial, nearly imposing themselves with the celestial as to make themselves seem like an after image. Think of this as someone moving their hand in front of a high speed lens and leaving behind an after image of their hand that follows split seconds behind their real hand. A mirror image as the namesake of the spell suggests, making it impossible to track which image is real. What the spell is saying it DOESN'T do is create 3 copies of the celestial that all stand around/beside/next to said celestial like "Hi, how are you doing, which one of us do you want to hit?"
Divine Sense allows the Paladin to open up his senses and divine the location, the effective space, of a celestial that is not behind total cover. They know for all intents and purposes that there is a Celestial in that effective space, that location, but they can't identify the celestial specifically. Just that it exists.
Let's put this into the setting.
There is a Celestial that seems to be moving so fast that there are 3 other images of itself that mimic its every move and action. I can't tell which one is the right one because they are so close together in its space, its location.
The Paladin uses Divine Sense. "Yep, there's definitely a Celestial right there, but because the mirror images are mimicking its every move so closely together in its space (its 5ft location), I can't really help pinpoint which one is real. Swing and hope you hit something!"
Lesson: Divine Sense is helpful for finding invisible creatures of the effected creature type, or figuring out if there is one in disguise parading around in some other form. Something that counters magic, such as Dispel Magic, is better for something like Mirror Image, as are AoE attacks.
Best Answer
Divine Sense can't target something behind total cover.
Your instincts are correct.
The rules on cover state:
The usage of the word "concealed" here is problematic, but I think the usage here is assuming you have a solid, non-transparent object providing your cover. I think the intent is clear – if an attack or effect would be blocked completely, then the target is behind total cover.
Since the paladin's Divine Sense feature cannot detect through total cover, I think you are in the clear. The sheet of ice acts much like a wall of force, except the ice can be damaged or broken through, and I'd rule that wall of force provides total cover to enemies on the other side, as it "makes the target more difficult to harm."
This ruling is further reinforced by an unofficial tweet by rules designer Jeremy Crawford from April 2016, in response to a question about whether wall of force provides cover:
This also serves to show that the use of the word "concealed" in the description of total cover was in error.