I understand that we’re supposed to compliment the bride to the groom by telling him how pretty and pious she is. I have two questions regarding this. Should we be looking at her in the first place such that we know that she’s pretty (particularly if she is)? And what if she’s not pretty, are we supposed to tell an untruth?
You are right. The Sages tell us that one has a special mitzvah to praise a kallah to her chatan. This is described as “the” reward at the wedding festivities (Berachot 6b). The Sages also said specifically that the praise one should say is that the kallah is “na’ah” – attractive and “chasuda” – pious.
You are also right that Judaism teaches that in order to preserve the dignity of a woman and maintain her integrity by focusing on her internal value and not her external beauty, a man is not supposed to gaze at a woman with the intention of enjoying her looks other than for the purpose of marriage.
So how do the Sages instruct us to compliment the bride’s beauty?
One answer is that a person should say the praise in the name of a woman he knows. For example: “My wife said your kallah is very pretty, which wasn’t a surprise for me since you’re so handsome”. Or, “I heard from my mother/sister/daughter that the kallah is quite attractive – and you should know that my mother etc. has good taste”. Another answer is that in order to enhance the chatan’s appreciation of his kallah, one is allowed to glance at her for this purpose, where one’s intention is not to enjoy her beauty but to increase the chatan’s value of it.
That being said, another approach to answering the question you raise is based on the idea that “na’ah” here is not intended to refer to her physical appearance, but rather to her disposition and deeds. Accordingly, the praise we’re instructed to say would be akin to: “Your kallah looks very sweet and kind; as well as being very righteous. I’ve heard wonderful things about her from everyone who knows her”.
Many people are accustomed to fusing both approaches by saying something like: “My wife thinks your kallah is adorable. She really does look very kind and gentle. We’ve both heard really wonderful things about her love of Torah and mitzvot. With the help of G-d, the two of you should make a great couple.”
Of course, since every new bride or groom has some uncertainty about this major choice in life, as well as some insecurity, not only is it a mitzvah to praise the kallah to the chatan, but it goes the other way around as well. And people should tell the kallah about what a special chatan she’s marrying. But in all cases, a person must praise in good taste and with tact, considering what is or is not appropriate for each case. For example, if the kallah is really exceptionally attractive and the chatan is clearly aware of it, and one also knows the chatan is sensitive to people looking at her, then one should omit any mention of her looks and emphasize only matters of character and Torah values.
What if there doesn’t seem to be much to praise on either front, did the Sages intend us to tell an untruth? The answer is that nevertheless we are to exaggerate (within plausible bounds) and, for several reasons, this is not considered being untruthful. For one, if the couple is getting married, each obviously found and finds favor with the other. When you praise, then, you are reinforcing whatever good things they see in each other. In addition, people generally don’t see the full good in others. We have a tendency to sell other people short of what they really are. Therefore, exaggerating a little likely brings us closer to the truth of who he or she really is. And last, since it is G-d’s desire to increase appreciation, harmony and love in marriage, enhancing the couple’s joy is His Truth.