How do pokemon choose their mates? And can they be attracted (not the move) to another simply because they have a pretty face?

It depends on whether you’re referring to a wild or a tame pokémon, anonymous. Wild pokémon typically choose mates based on suitability, which itself is actually a combination of factors, including hardiness, health, and physical attractiveness. Tame pokémon focus less on the first two factors and more on both physical and mental attraction (or, in other words, a combination of looks and personality, much in the same way humans choose their mates), largely because the need for a hardy mate is less important when a pokémon has someone to care for them.

Of course, beyond that, it also depends on the pokémon itself. For example, to psychic-types, intelligence or empathy may be seen as attractive traits, grass-types sometimes seek out the best-smelling mate, and male fighting-types, for reasons that are somewhat (but not entirely) beyond yours truly, are attracted most to females who can defeat them resoundingly in battle. And even then, what determines attractiveness to one member of a type may be different from the definitions held by all other members. For example, magikarp select mates who can propel themselves the highest while using Splash, which is something no other water-type looks for (seeing as Splash is otherwise not a particularly useful skill, generally speaking).

In short, yes, some pokémon can be attracted to a pretty face and not much else, but there are a wide variety of factors that go into what defines an ideal mate in each species.