Question

First question here. I have a very raw understanding of sexualselection:

Say a group of females of a certain species "likes" some featureof a certain groups of males; by "like" I mean some behaviour thatmakes this group of females tend to mate with males having thisfeature, then the females are selecting their genes which make themfeel appealed to males with the feature, and then this processbecomes exponent since the group of females becomes bigger andforces the population of males to have this feauture, until anequilibrium is reached. Althought I know this also happens with theroles interchanged.

My first question is, why do females tend to like males thathave high amounts of these features, more than the average in thepopulation?

My second question is, why do the end products of theseselections are such beautiful features? Perhaps this may sound alittle arrogant but I don't understand how an animal can appreciatethis beauty, I suppose this is to make some sort of selection ofhealthy males.

Thanks