(As an aside, it should be noted the the artist who titled her work is not a native English speaker.)
The problem is, in this case, the preposition "till" ('til, until) is orthographically identical to the verb "till" (labour, cultivate, plough). And when the verb is in first position, usually one of two structures follow: questions, and imperatives. As most of us know, classical grammar requires a simple inversion of the subject-verb in the declarative clause in order to form a question. For example:
But of course, our current variety of English normally employs the curious verb "do" (for all verbs except auxilliary/modals): "Do you think she's beautiful?"
"He is a man" -> "Is he a man?"
"You think she's beautiful" -> "Think you she's beautiful?"
The imperative is normally distincted from the elision of the subject, which is seemingly always second-person. Thus, "clean [you] the desk," or "buy [you] the tickets."
In "Till the end with you," there is clearly no subject, since the first word is followed by a noun phrase "the end" (or "the end with you", depending on how you read it!) Thus, the first instinct is that this is an imperative. Moreover, the ending "with you" is commonly seen for emphasis in select imperatives:
"be off with you!"Thus, my first interpretation of "Till the end with you", was somewhat of a mixture between an emphatic statement to the reader to cultivate the end of something, possibly a field, OR a clumsy statement of the artist, expression her desire to cultivate land together with the reader.
"fly to Siberia with ye!"
After I realised what was meant, I started considering what could be changed. A dry replacement for the preposition obviously wouldn't be enough: "until the end with you" could mean something like "waiting for your demise". The only solution, really, was to swap the two adverbials into "With you 'til the end". An [uncontextualised] statment that begins with "with", can be taken to have elipsed "I am" at the beginning. Thus, "with you till the end" is really "I am with you until the end [of the world]".
And yet, I still have trouble understanding how or why anybody would have written the line in the opposite order. I suppose there could be a pause between the two: "Till the end, with you", but that slows the pace. Although maybe that's intended. Personally, I prefer the quick and succinct when it comes to titles, and I'm also partial to ones that make you think instead of the dry, literal and unimaginative titles of most research papers. (e.g. "Strategy for Determination of in Vitro Protein Acetylation Sites by Using Isotope-Labeled Acetyl Coenzyme A and Liquid Chromatography−Mass Spectrometry".)