OK, to answer the question posed by the title: Can you blog from your mobile? Well, yes and no.
Yes. Because you can put your thoughts down anytime and anywhere. You can think properly about what you want to say and work on the many eloquent ways that will give the reader the best mental imagery.
No, because......there's that vibrating again....because screens on small devices can be quite limiting and smartphones have the added disadvantage of being of little use in sunlight.
I am writing this via WordPress for Android and barring the odd typo—not my typo but the auto correcting typo—you can flesh out your thoughts and develop your ideas. You can add to your day by utilizing one of these devices to better your grammar or think about something seriously and amend it to perfection before you submit it to your audience.
And while it is not quite there yet, there is the voice recognition system that, once perfected, will allow us all to speak our minds into our mobiles. Now there is an app for the future. Voice to WordPress. Let's abbreviate it to VW.