what does the announcement mean?

OK I'm new to this so please forgive me if this question is too basic.

LHG have announced they want to issue another 1,890,495 shares at $1.55

First of all how? Who will pay $1.55 when the last transaction was $1.43 ???

Second of all, how can companies keep issuing shares? What are the limits to doing this?

Thirdly, is this going to pull the sp down any further? After all it must dilute the value of existing shares to some extent.

I would appreciate some guidance here, thanks in advance.