Maybe you were
overdressed for the interviews. Is that a possibility? It's tough for us to know if she was being honest or something else since we don't know how you were dressed. It is possible to be overdressed for an interview, and if you are, it's not going to make a good impression on the person interviewing you. So she might have just been giving you good advice. This isn't to say that she couldn't have also just been nasty, but again, it's tough to know.
I have to tell you that based on what you've written here it seems like you might be somewhat fixated about how you look, or about what she thinks about you. I say this because you admit to asking her essentially the same question three time during the course of your outing. This could indicate obsessive behavior.
I also say this because her reply “I would never even tell you if I liked something you were wearing because if I didn’t say I liked what you were wearing the next day you would get upset”.
on it's face doesn't sound all that terrible, especially if you are a bit fixated on how you look.
Your account of the conversation starts with you saying to your mother:
"Are you really putting down my clothes?"
Presumably, she said something about your clothes before you asked her this question. What did she say?
Obviously you know your mother a whole lot better than we do, and so you should have a good idea when she is being sarcastic and when she is not, but sometimes people hear sarcasm when none is intended. Is it possible that she wasn't being sarcastic or you sure about this?
Also, she happened to be correct when she said "There are some days one looks better than others,"
and "The hair can look better some days than others, one has no make up on."
Again, on the face of it, this doesn't seem all that insulting and yet you've told us that the first comment got you upset.
Your mother is 88 which could explain her use of "one" as a pronoun, but I can also imagine that she used it because she knew that if she had used "you" instead it would get you upset.
"I would never tell you when you look great,"
if taken out of context sounds like a mean thing to say, but you've already told us that she explained her reason for not doing so, and whether or not it was sincere, it's something much different than her saying "I would never tell you when you look great because I want you to always worry that you don't"
or "...because I never do; you always look terrible."
If you have reason to believe that this is actually what she meant, then you would have a very legitimate reason to be upset. However you've also told us that this comment of hers made you angry because she implied that you don't look good unless she thinks so
First of all, it sort of goes hand in hand that, unless you're trying to be kind rather than honest, you tell people how they look based on how you think they look. It would be a little strange to expect her to recognize that you look good if she didn't think you did.
Of course it would be reasonable to expect your mother to tell you that you looked good even if she thought you only looked OK. (I hope you would not want her to tell you you looked good if you obviously did not. Telling someone they look good when they are wearing raggedy pants, a tattered blouse and their hair is all over the place, and their face is caked with yesterday's make-up isn't doing them any favor.) However, reading your account, I certainly didn't infer from your mother's comment that she meant that her opinion on your looks is all that matters,
Again, it's tough to to draw any conclusions here without a lot more information, and there's some reason to think that what you considered nasty comments about how you look may not have really been all that nasty, but I figure that if it was really clear in your mind that your mother is a nasty old shrew and is and was being mean to you, you wouldn't be asking for our interpretation of her remarks. That you are, suggests to me that you're not certain yourself.
So I return to my original question: Is it possible that she wasn't being nasty, or even that she is tired of fighting with you because you may be a bit fixated on how you look and no matter what she says, you get upset?
If these are not possible, then I'm not sure why you need our interpretation of her comment. If they are not possible then she was being nasty and you don't need us to tell you that.
If they are possible though then you may need to talk to someone, other than your mother, about how you feel about your looks. A good friend, a sister or some other relative or even a pastor or counselor.
In any case, it's tough for me to give you advice without knowing more about your situation and the discussion/argument you had with your mother.