I'm sorry Capacra. I disagree with you. This (these) is used when the thing is close you. You can touch it. In Portuguese, there isn't clearly difference between "essa" and "esta". That (those) is used when the thing isn't close you. You can only point it and not touch or get it.
Hi criscard, I agree with you that this/these is used for stuffs near you and that/those is used for stuff far from you. But I disagree that there isn't a clearly difference between "essa" and "esta" in Portuguese, if you do a search about it you'll find that it's the same difference than in English. The words I translated in my comment before were related to the online michaellis dictionary, so, I'm sure about it. I had the same doubt about this two words some time ago, then I searched and I found this difference. I liked a lot this site: http://renatafraia.blogspot.com.br/2010/05/esta-ou-essa-quando-usar-gramatica.html to explain the difference. I wish I helped you, if you think I'm still wrong please send another message to explain me why, good studies. :)
Essas maçãs (estão perto do ouvinte) Ex: João que está distante de Maria, diz - Maria, pegue essas maçãs - Maria que está perto das maçãs diz - Quais, estas maçãs aqui do meu lado (percebe o uso do estas?) ou "aquelas" (aquelas - está longe dos dois) que estão perto do fogão? Explicou ou complicou?? kkkkk
Mas em resumo é assim: isto - está perto do falante isso - está perto do ouvinte aquilo - está longe dos dois